Environmental Health Perspectives Research Articles

Letter from the Editor-in-Chief

Vol. 122, No. 4 EditorialOpen AccessLetter from the Editor-in-Chief Hugh A. Tilson Hugh A. Tilson Search for more papers by this author Published:1 April 2014https://doi.org/10.1289/ehp.1408430Cited by:3View Article in:中文版AboutSectionsPDF ToolsDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InReddit The first day of August 2014 will be a big day for me. I have decided to retire after nearly 40 years of federal service, and Environmental Health Perspectives (EHP) will need a new editor-in-chief. It has been a real privilege to lead this important scientific journal since 2008. I believe in EHP, the science it supports, and the communities it serves, and I am proud to have had a part in the journal’s continued success and growing impact.In my inaugural editorial as editor-in-chief (Tilson 2008), I wrote that EHP must adhere to the principles of independence, transparency, and balance and be prepared to recognize emerging themes in order to attract a wider audience and have an impact on the field. Adherence to these standards has served the journal well. In 6 years, the journal’s impact factor increased from 5.86 to 7.26. EHP is one of the top-ranked journals in Public, Environmental, and Occupational Health and in Environmental Sciences. The journal receives nearly 1,500 research manuscripts each year and has an acceptance rate of 15%. We have more than 40 internationally recognized members of the Board of Associate Editors and more than 100 active members of the Editorial Review Board. The journal routinely publishes highly recognized news articles on a variety of emerging topics in environmental health research. In collaboration with the Shanghai Center for Disease Control and Prevention, we also publish news and other articles in a bimonthly issue of EHP Chinese Edition. The journal established and cultivated a thriving social media presence on Facebook and Twitter, and updated its format to provide easy access on personal communication devices. In 2013, EHP was one of the first environmental health journals to publish exclusively online, with the entire journal available electronically and free of charge.I thank the leadership of the National Institute of Environmental Health Sciences (NIEHS) for providing continuous and enthusiastic support and for making good on its commitment to editorial independence and unfettered scientific peer review. The EHP staff members also deserve my gratitude and thanks. They are of some of the most dedicated and passionate individuals I have ever known. I believe that the articles and news we published have made a significant contribution to improving human health and have provided the best available information for decision makers and policy makers worldwide. I am confident that my successor will find the NIEHS and the EHP staff eager to carry on this tradition of excellence.The NIEHS is organizing a search committee to recruit my replacement. I have agreed to assist with the transition and, if necessary, will happily work as a volunteer until a new editor-in-chief is named. In the meantime, EHP will continue to receive manuscripts and publish research and news stories each month. Keep sending us your science, and by all means, keep reading EHP !The author declares he has no actual or potential competing financial interests.ReferenceTilson HA. 2008. Building on a firm foundation. [Editorial]Environ Health Perspect 116:A12; doi:10.1289/ehp.1113118197275. Link, Google ScholarFiguresReferencesRelatedDetailsCited by Feng Q, Liu S, Mao Z, Xu J, Wang Z and Le X (2016) Highlights and new Editorial Advisory Board members of the Journal of Environmental Sciences, Journal of Environmental Sciences, 10.1016/j.jes.2016.08.003, 47, (1-6), Online publication date: 1-Sep-2016. van der Kamp J and Bachmann T (2015) Health-Related External Cost Assessment in Europe: Methodological Developments from ExternE to the 2013 Clean Air Policy Package, Environmental Science & Technology, 10.1021/es5054607, 49:5, (2929-2938), Online publication date: 3-Mar-2015. Birnbaum L and Woychik R (2014) Retirement of Hugh A. Tilson, Environmental Health Perspectives, 122:8, (A202-A202), Online publication date: 1-Aug-2014. Vol. 122, No. 4 April 2014Metrics About Article Metrics Publication History Originally published1 April 2014Published in print1 April 2014 Financial disclosuresPDF download License information EHP is an open-access journal published with support from the National Institute of Environmental Health Sciences, National Institutes of Health. All content is public domain unless otherwise noted. Note to readers with disabilities EHP strives to ensure that all journal content is accessible to all readers. However, some figures and Supplemental Material published in EHP articles may not conform to 508 standards due to the complexity of the information being presented. If you need assistance accessing journal content, please contact [email protected]. Our staff will work with you to assess and meet your accessibility needs within 3 working days.

Environmental health perspectives in Central China

Welcome to this Special Issue of Indoor and Built Environment. This issue provides the environmental health perspectives of air pollution control in Central China and looks into research development regarding the dispersion of pollutants, control of indoor moisture thus reducing microbial proliferation whilst enhancing thermal insulation properties of walling materials, personal ventilation and sleep quality; it also surveys the increasing prevalence of childhood respiratory and allergy diseases such as asthma and pneumonia in children in association with the ambient air pollution and indoor environment, particularly with the use of airconditioning/humidifier equipment and in relation with building characteristics of typical Chinese homes in Central China such as in Shanghai, Nanjing, Chongqing, Wuhan and Changsha where there has been a steady rise in prosperous growth in average household income, commercial goods and in industrial production which has improved the life style for many Chinese families. However, the environmental cost in relation to adverse health effects particularly of children should be evaluated, so that appropriate remediation technologies and regulatory standard can be effectively implemented to reduce environmental deterioration particularly for housing and urban developments. Environmental health is now an important government policy in China, to improve the environmental quality for the Chinese citizen which has become imperative especially considering the environmental pollution that has been prevalent in almost all Chinese cities in recent years. Outdoor air pollution is one of China’s most serious environmental problems. Burning of coal is the major source of energy in China, contributing to about 75% of all energy consumption for industrial processes, domestic and commercial heating and cooking. Consequently, coal smoke with suspended particulate matter (PM), nitrogen oxides (NOx) and sulphur dioxide (SO2) are the major air pollutants in ambient environment. The increasing rise in the usage of motor vehicles in many Chinese cities has also contributed to the air pollution cocktail mixture in ambient air, with inhalable particular matters (PM10, PM2.5), SO2, and NOx being the critical pollutants of concern and these are now prominently featured for air quality standard regulation in China. Also, as the average household income is better off for many families, there is an increasing demand for western consumer’s goods and better furnishing and fitting of their home interior and increasingly many types of indoor air pollutants such as formaldehyde and volatile organic compounds (VOCs) typically found in western countries in relation to the use of composite wood-based products, adhesives, sealants and various types of coatings and vinyl floorings are found in high concentrations in these Chinese homes. The emissions of VOCs and formaldehyde could cause adverse health effects to occupants and there are requirements in the Chinese standard for certificating the emissions from building products and indoor air concentrations in newly built housings. There has been a steady political pressure for development of air-tight and energy-efficient buildings to commensurate with demand for growth of sustainable development of green buildings. Chinese standard maker are facing the dilemma of having requirement for reducing indoor air pollution and maintaining the comfort factor of buildings, whilst demanding higher energy efficiency standard. Central China (Yangtze valley Region) has a dense population and is an important economic development region of China where there has been a rapid growth in urban and industrial development. The economic growth in the region has been accompanied by a huge concomitant widespread growth in residential construction in the past 10 years. The region is situated within the hot summer and cold winter zone in China; characterized by the wet cold winters, very hot and humid summers. The temperature difference between day and night is normally small, with a minor daily temperature range. The housings in the region of Central China would experience a high level of humidity, particularly

Microbial ecology, bacterial pathogens, and antibiotic resistant genes in swine manure wastewater as influenced by three swine management systems

The environmental influence of farm management in concentrated animal feeding operations (CAFO) can yield vast changes to the microbial biota and ecological structure of both the pig and waste manure lagoon wastewater. While some of these changes may not be negative, it is possible that CAFOs can enrich antibiotic resistant bacteria or pathogens based on farm type, thereby influencing the impact imparted by the land application of its respective wastewater. The purpose of this study was to measure the microbial constituents of swine-sow, -nursery, and -finisher farm manure lagoon wastewater and determine the changes induced by farm management. A total of 37 farms were visited in the Mid-South USA and analyzed for the genes 16S rRNA, spaQ (Salmonella spp.), Camp-16S (Campylobacter spp.), tetA, tetB, ermF, ermA, mecA, and intI using quantitative PCR. Additionally, 16S rRNA sequence libraries were created. Overall, it appeared that finisher farms were significantly different from nursery and sow farms in nearly all genes measured and in 16S rRNA clone libraries. Nearly all antibiotic resistance genes were detected in all farms. Interestingly, the mecA resistance gene (e.g. methicillin resistant Staphylococcus aureus) was below detection limits on most farms, and decreased as the pigs aged. Finisher farms generally had fewer antibiotic resistance genes, which corroborated previous phenotypic data; additionally, finisher farms produced a less diverse 16S rRNA sequence library. Comparisons of Camp-16S and spaQ GU (genomic unit) values to previous culture data demonstrated ratios from 10 to 10,000:1 depending on farm type, indicating viable but not cultivatable bacteria were dominant. The current study indicated that swine farm management schemes positively and negatively affect microbial and antibiotic resistant populations in CAFO wastewater which has future “downstream” implications from both an environmental and public health perspective.

A Question for Women's Health: Chemicals in Feminine Hygiene Products and Personal Lubricants

Vaginal research got a desperately needed boost at the National Institutes of Health (NIH) in 1992. That’s when Penny Hitchcock took over the Sexually Transmitted Diseases Branch at the National Institute of Allergy and Infectious Diseases and Nancy Alexander became chief of the Contraceptive Development Branch in the NIH Center for Population Research—posts previously held by men. “Those two got together and discovered NIH had no programs for vaginal research,” says Richard Cone, a Johns Hopkins biophysics professor. Cone had begun developing vaginal contraceptives that would protect against sexually transmitted infections (STIs) in 1980, and until then, struggled to get funding. Mucous membranes in the vagina and vulva rapidly absorb chemicals without metabolizing them. But until recently scant research existed on how chemicals in feminine hygiene products and personal lubricants may affect women’s health. Hitchcock and Alexander soon initiated research programs on vaginal physiology, immunology, and microbicides, eventually funding Cone’s work. These new programs led to groundbreaking discoveries in animals and humans that certain chemicals—including glycerin (glycerol), a common base for personal lubricants—can damage or irritate vaginal1 and rectal2 epithelial cells, potentially increasing the transmission of STIs such as herpes and human immunodeficiency virus. When it comes to reproductive health, research on contraceptives and STIs continues to garner interest worldwide. But a related area—chemical exposures from feminine hygiene products and personal lubricants—has received much less attention. In the United States alone, women spend well over $2 billion per year on feminine hygiene products,3 including tampons, pads, feminine washes, sprays, powders, and personal wipes. But until recently, scant research existed on how chemicals in these products may affect women’s health. As scattered findings emerge, several scientists and interest groups are calling for more research to fill in the gaps.4,5 A recent report by the nonprofit Women’s Voices for the Earth (WVE) points out that feminine hygiene products may use ingredients that are known or suspected endocrine-disrupting chemicals (EDCs), carcinogens, or allergens. And while nearly all women use tampons and sanitary pads, black and Latina women use douches, wipes, powders, and deodorizers more often than women of other races, putting them at greater risk of potential chemical exposures.4 “It’s a little bit edgy. People have been shocked, saying things like ‘I’ve never really thought about [the vagina] being an important internal link to your body,’” says Alexandra Scranton, director of science and research for WVE. “Although it is well known that the vaginal ecosystem is more sensitive and more absorbent than typical skin, there is surprisingly little research out there on feminine care products.” Surveys conducted in the 1990s–2000s gave a sense not only of how commonly some products are used but also how widely use can vary across racial/ethnic groups.

Instruments for Assessing Risk of Bias and Other Methodological Criteria: Krauth et al. Respond

Instruments for Assessing Risk of Bias and Other Methodological Criteria: Krauth et al. Respond

PFCs and Early Menopause: Association Raises Questions about Causality

Polyfluoroalkyl chemicals (PFCs)—chemicals used in the manufacture of stain- and water-repellant products—are suspected endocrine disrupters.1 Animal studies have suggested an association between exposure to two of the most commonly encountered PFCs (perfluorooctanoate, or PFOA, and perfluorooctane sulfonate, or PFOS) and altered hormonal function,1,2 although evidence in humans remains inconsistent. A small number of cross-sectional epidemiological studies have reported an association between PFOA/PFOS exposure and timing of puberty,3 menopause,4 and thyroid function,5 while others have reported no association.6 In this issue of EHP, researchers report an association between PFC concentrations in circulating blood and rate of hysterectomy as well as earlier age at natural menopause.7 The findings, say the researchers, raise the question of whether high PFC exposure may lead to early menopause or, conversely, whether early menopause may lead PFCs to build up in women’s bodies. Either way, the results are of interest because women who reach menopause by their late 40s are at increased risk for various forms of heart disease.8,9,10 “If PFC levels are predictors of earlier menopause,” the investigators write, “exposure may also increase the risk of other serious health outcomes (e.g., cardiovascular disease and stroke).”7 According to the North American Menopause Society, menopause occurs, on average, at age 51 in U.S. women. Women characterized as having early or premature menopause will have had their last menstrual period before age 40.11 In the current study, researchers from the National Institute of Environmental Health Sciences (NIEHS) and the University of North Carolina at Chapel Hill analyzed data for 2,732 women, more than two-thirds of whom were premenopausal. The investigators compared blood concentrations of four PFCs—PFOA, PFOS, perfluorononanoate (PFNA), and perfluorohexane sulfonate (PFHxS)—and, for postmenopausal women, age at natural or surgically induced menopause. The data were collected as part of the National Health and Nutrition Examination Survey (NHANES) between 1999 and 2010. NHANES data are intended to be nationally representative, and past analyses have indicated ubiquitous exposure to PFOS, PFOA, and other PFCs. One 2007 NHANES analysis showed that 98% of adults sampled had measurable levels of at least two PFCs in their blood.12 In the current study, women with the highest blood levels of PFOA, PFNA, and PFHxS were, respectively, 36%, 47%, and 70% more likely to have experienced menopause than women with the lowest concentrations of these compounds. Premenopausal women had the lowest levels of all four PFCs, whereas women who had undergone hysterectomy had the highest levels.7 PFHxS was most strongly associated with rate of hysterectomy. Women with the highest blood levels were 3.5 times more likely to have had a hysterectomy than women with the lowest levels. PFOA, PFNA, and PFOS were also significantly associated with having had a hysterectomy.7 Hysterectomy was associated with the highest blood levels of all four PFCs studied, possibly a result of unusually early menopause— although longitudinal studies are necessary to test that hypothesis. Women in the study reached natural menopause at a median age of 49, while women who had hysterectomies reported their last period at a median age of 38. The cross-sectional nature of the study makes it impossible to distinguish whether higher PFC levels may have led to earlier menopause or vice versa. “PFCs circulate in blood, so menstruating women may lose PFCs through blood loss, which would not be the case for postmenopausal women,” says lead author Kyla Taylor, a health scientist at the NIEHS. Whereas many persistent organic pollutants are stored primarily in fat tissue, PFCs form bonds with blood proteins. That means they tend to accumulate in serum rather than in fat. “While this study suggests the potential for reverse causation in the association between PFCs and earlier menopause, we don’t know what that means or whether it’s the sole explanation [for the association],” says Sarah Knox, an epidemiologist at West Virginia University who studies PFCs but was not involved in this research. Only a longitudinal study can provide the insight to determine causality. “This is an area of concern and an area clearly in need of further research,” Knox says.

Fighting Noise Pollution: A Public Health Strategy

In this issue of EHP, investigators from the University of Michigan at Ann Arbor describe the most serious health effects of noise and propose a blueprint for an effective U.S. public health response.1 The team, led by Richard L. Neitzel, an assistant professor of environmental health sciences, estimated that nearly one-third of Americans are exposed to noise levels deemed injurious to hearing by the U.S. Environmental Protection Agency (EPA)—a 24-hour average noise level exceeding 70 dBA.1 The authors based this figure on 1981 estimates from the EPA.2 But mounting evidence also connects noise exposures with cardiovascular disease, sleep disturbance, stress, general annoyance, impaired learning and concentration, and other health effects. The EPA’s limit for protecting against all health effects of noise is a 24-hour average 55 dBA, weighted with a penalty for nighttime exposures to account for the special impact of disrupted sleep.2 In 1981 the EPA estimated about 3% of the U.S. population could be exposed to noise levels high enough to increase the risk of hypertension.2 A recently implemented labeling requirement in Europe advises consumers about tires’ noise emissions as well as their energy economy and wet braking distance. Noise activates the body’s sympathetic nervous system, raising blood pressure and heart rate.3 Although inhabitants of noisy environments may be able to tune out noise, that habituation does not appear to extend to the cardiovascular system during nighttime exposures.4 Repeated arousals have been reported to prevent blood pressure from dropping during sleep the way it’s supposed to.5 Disrupted sleep is also associated with increased levels of lipids and the stress hormone cortisol, potentially increasing the risk of disorders such as depression6 and atherosclerosis.7 Two 2013 studies involving millions of British residents living airports reported an association between exposure to aircraft noise and increased hospital admissions for cardiovascular diseases.8,9 Annoyance can increase sympathetic tone—that is, put the sympathetic nervous system on high alert—especially in sensitive individuals.10 This increase in sympathetic tone has been postulated as a pathway by which individuals with high occupational noise exposures develop heart disease.”11 The major sources of chronic unwanted noise in the United States include road, rail, and air transportation,12 although adverse health effects are possible with enjoyable sources—loud sporting events, firearms, and music, for example.1 The authors advocate two approaches as the “least costly, most logistically feasible, and most effective” federal-level interventions: direct regulation of noise emissions, and improved public education. Between 1981 and 2000, regulation of aircraft noise under the Noise Control Act of 1972 drastically reduced the number of people exposed to excessive noise from neighboring airports, even though air travel increased sixfold in the same period.13 The EPA retains regulatory authority to reduce noise exposures from other sources, despite the 1981 defunding of its Office of Noise Abatement and Control. But the agency’s funding peaked in 1978, rendering action on noise control unlikely without congressional support, according to Neitzel and colleagues.1 Another strategy, labeling products with their noise emissions, is already mandatory for some products in the European Union, Argentina, Brazil, and China, and has been implemented in the United States for air compressors. The authors point out that labeling is only effective if consumers understand what they are reading; public education is critical. The authors also recommend comprehensive noise mapping at the national level to identify hot spots for further study and remediation. The necessary data could be collected relatively inexpensively through crowdsourcing using people’s cell phones, Neitzel says: “We have a minicomputer in our pockets, every one with a microphone, and existing software platforms can compile noise data.” They also recommend sustainable building design and municipal procurement policies that consider noise levels when purchasing noisy items such as emergency vehicles, construction equipment, and buses. Experts studying community noise highlight the need for controlling noise at the source. Arline Bronzaft, an environmental psychologist and professor emerita of City University of New York, cautions that communities that are quiet today “could be intruded upon in the near future.” It’s therefore important to focus on quieting communities overall, not just separating people from noise today, she says. Others point out the need to consider noise as part of a holistic approach to public health. As one example, Hugh Davies, an associate professor in the School of Population and Public Health at the University of British Columbia, says efforts to mitigate traffic emissions must be achieved in ways that don’t increase noise levels. Distancing houses from vehicles reduces exposures to both noise and vehicular emissions, but reducing air pollution by reducing stop-and-go traffic may actually increase noise, because faster traffic is often noisier. Thus, Davies say, “we are replacing one health hazard with another.”

Once Upon a Mine: The Legacy of Uranium on the Navajo Nation

On a low, windswept rise at the southeastern edge of the Navajo Nation, Jackie Bell-Jefferson prepares to move her family from their home for a temporary stay that could last up to seven years. A mound of uranium-laden waste the size of several football fields, covered with a thin veneer of gravel, dominates the view from her front door. After many years of living next to the contamination and a litany of health problems she believes it caused, Bell-Jefferson and several other local families will have to vacate their homes for a third round of cleanup efforts by the U.S. Environmental Protection Agency (EPA). Decades of uranium mining have dotted the landscape across the Navajo Nation with piles of contaminated mine waste. The EPA has mapped 521 abandoned uranium mines on the reservation, ranging from small holes dug by a single prospector into the side of a mesa to large commercial mining operations.1 The Navajo people did not have a word for “radioactivity” when mining outfits looking for vanadium2 and uranium3 began moving onto their land in the 1940s, and they did not understand that radiation could be dangerous. They were not told that the men who worked in the mines were breathing carcinogenic radon gas and showering in radioactive water, nor that the women washing their husbands’ work clothes could spread radionuclides to the rest of the family’s laundry. Bell-Jefferson and her brother Peterson Bell played in and around the mines, splashing and swimming in pools of radioactive water that had been pumped out of the mines and then collected on their property. The contaminated water looked and tasted perfectly clean. Families used it for cooking, drinking, and cleaning. Hogans and corrals were built with mine wastes, as were roads. All that changed on 16 July 1979. Just about a mile and a half from Bell-Jefferson’s home, a dam broke at the United Nuclear Corporation mill, where workers processed ore from the nearby Northeast Church Rock uranium mine. The spill dumped 94 million gallons of mill process effluent and 1,100 tons of tailings—an acidic, radioactive sludge—into a large arroyo that emptied into the Puerco River.4 The Church Rock spill occurred less than four months after the partial meltdown of the Three Mile Island nuclear reactor, and it released three times as much radiation, making it the biggest nuclear spill in U.S. history, yet it received only a tiny fraction of the news coverage.5 Declared a Superfund site in 1983, the heaps of waste around the mill still cause radiation survey instruments to squeal from the invisible uranium atoms that remain active 30 years later.6 “This area used to be my playground,” Bell-Jefferson says. “Now it’s just a huge wound.” For the Bells and other Dine (the term by which many Navajo people refer to themselves), the Church Rock spill was a turning point. When corporate and government officials appeared in the spill’s aftermath and began inquiring into exposure to the slurry and potential health problems, the Navajo people finally learned the truth—far from being harmless, these uranium mines were poisoning people, and researchers say they will continue to do so for decades to come.

Addressing the Burden of Disease Attributable to Air Pollution in India: The Need to Integrate across Household and Ambient Air Pollution Exposures

Addressing the Burden of Disease Attributable to Air Pollution in India: The Need to Integrate across Household and Ambient Air Pollution Exposures

Making environmental health interesting for medical students-internet assisted facilitated collaborative learning approach.

Background:Topics on environmental health are usually neglected by students and it is necessary for them to learn this area with a public health perspective as environment plays a vital role in multi-factorial causation of diseases. Hence there is a need for alternative teaching/learning methods to facilitate students in acquiring the required knowledge.Objectives:To increase the student interest and enhance their participation in acquiring knowledge in public health perspective of environmental health. Teaching Objectives/Learning Were: At the end of the session students should know the importance of air as an environmental factor in disease causation in special reference to public health hazards, the major sources of air pollution, major pollutants causing the health hazards, the way to measure pollutants and control them.Materials and Methods:The whole class of students was divided into two batches and one session was planned for each batch. Each batch was divided into six small groups. The groups were given task of exploring the internet on the different topics mentioned in the learning objectives. All the students were asked to explore, compile information and collectively prepare a presentation and present their findings based on their reviews. Students’ feedback was collected at the end of each session.Results:Eighty five percent of them were clear about the learning objectives and interested about internet learning. Most of them gave a positive opinion about the newer teaching learning method.Conclusions:Internet assisted group study served as a valuable alternative, innovative, and interesting tool to teach and learn the environmental health as revealed by students’ feedback.

In Support of EHP ’s Proposal to Adopt the ARRIVE Guidelines

In Support of <i>EHP</i> ’s Proposal to Adopt the ARRIVE Guidelines

EHP Classic Paper of the Year, 2013

Vol. 121, No. 9 EditorialOpen AccessEHP Classic Paper of the Year, 2013 Hugh A. Tilson Hugh A. Tilson Search for more papers by this author Published:1 September 2013https://doi.org/10.1289/ehp.1307395Cited by:1AboutSectionsPDF ToolsDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InReddit Environmental Health Perspectives (EHP) established the Paper of the Year in 2008 (Tilson 2008) as a way of highlighting high-quality articles published in the journal. The EHP Classic Paper of the Year is given to the most highly cited Research Article, Commentary, or Review Article over the preceding 60 months. We are proud to announce that the 2013 EHP Classic Paper of the Year is “Effects of Particulate Matter on Genomic DNA Methylation Content and iNOS Promoter Methylation” by Letizia Tarantini, Matteo Bonzini, Pietro Apostoli, Valeria Pegoraro, Valentina Bollati, Barbara Marinelli, Laura Cantone, Giovanna Rizzo, Lifang Hou, Joel Schwartz, Pier Alberto Bertazzi, and Andrea Baccarelli, published in the February 2009 issue of EHP.Tarantini et al. (2009) investigated molecular mechanisms underlying health effects of particulate matter exposures using biomarkers of DNA methylation that reflect reprogramming of gene expression. Their 2009 publication was one of the first to report application of epigenetic markers in an environmental or occupational health context.This research has had a significant influence on human environmental health research. The study by Tarantini et al. (2009) was one of the first studies to report evidence that DNA methylation may be altered in response to short-term exposures, and that it may reflect effects of usual levels of exposure over longer periods of time as well. This study also showed that easy-to-collect biospecimens, such as whole blood samples, and stored archival samples could be used to study effects of exposures on the epigenome. Novel laboratory and statistical approaches used in the study have since become routine in research on the epigenetic effects of environmental agents.EHP congratulates Tarantini and colleagues for their sustained contribution to the environmental health science literature. They should be recognized for their outstanding contribution to the rapidly evolving field of environmental epigenetics.ReferencesTarantini L, Bonzini M, Apostoli P, Pegoraro V, Bollati V, Marinelli Bet al.. 2009. Effects of particulate matter on genomic DNA methylation content and iNOS promoter methylation.Environ Health Perspect 117:217-222;doi:10.1289/ehp.1189819270791. Link, Google ScholarTilson H. 2008. EHP papers of the year, 2008.Environ Health Perspect 116:A234;doi:10.1289/ehp.11684. Link, Google ScholarFiguresReferencesRelatedDetailsCited byTilson H (2013) EHP Paper of the Year, 2013, Environmental Health Perspectives, 121:11-12, (A322-A322), Online publication date: 1-Nov-2013. Vol. 121, No. 9 September 2013Metrics About Article Metrics Publication History Originally published1 September 2013Published in print1 September 2013 Financial disclosuresPDF download License information EHP is an open-access journal published with support from the National Institute of Environmental Health Sciences, National Institutes of Health. All content is public domain unless otherwise noted. Note to readers with disabilities EHP strives to ensure that all journal content is accessible to all readers. However, some figures and Supplemental Material published in EHP articles may not conform to 508 standards due to the complexity of the information being presented. If you need assistance accessing journal content, please contact [email protected]. Our staff will work with you to assess and meet your accessibility needs within 3 working days.

The Environment Within: Exploring the Role of the Gut Microbiome in Health and Disease

The human genome codes for approximately 23,000 genes,1 yet some experts have suggested that the total information coded by the human genome alone is not enough to carry out all of the body’s biological functions.2 A growing number of studies suggest that part of what determines how the human body functions may be not only our own genes, but also the genes of the trillions of microorganisms that reside on and in our bodies. The genomes of the bacteria and viruses of the human gut alone are thought to encode 3.3 million genes.3 “The genetic richness and complexity of the bugs we carry is much richer than our own,” says Jayne Danska, an immunologist at the Hospital for Sick Children Research Institute in Ontario, Canada. “They serve as a buffer and interpreter of our environment. We are chimeric organisms.” Figure 1 False-color scanning electron micrograph shows the surface of the colon mucosa with pink clusters of rod-shaped bacteria, possibly Escherichia coli, attached. The genomes of the bacteria and viruses of the human gut alone are thought to encode 3.3 million ... A role for gut microbes in gastrointestinal function has been well documented since researchers first described differences in the fecal bacteria of people with inflammatory bowel disease.4 The molecular mechanisms responsible for the gut microbiome’s impact on metabolism and diseases throughout the body remain largely unknown. However, researchers are beginning to decipher how the microorganisms of the human intestinal tract influence biological functions beyond the gut and play a role in immunological, metabolic, and neurological diseases.

Arsenic Levels in Chicken

I commend Nachman et al. (2013) on their careful study of arsenic content in market samples of chicken and am dismayed to learn that arsenic levels in chicken remain high despite our report of arsenic levels in Environmental Health Perspectives in 2004 (Lasky et al. 2004). One possible explanation is the very complicated lines of authority around the regulation of drugs fed to food animals, along with the enforcement of those regulations. Nachman et al. (2013) focused their discussion on the role of the Food and Drug Administration (FDA), but many other agencies participate in the regulation and enforcement of residue safety in food animals. As noted by the Food Safety and Inspection Service (FSIS) in the introduction to their 2012 Residue Sampling Plans (FSIS 2012), The U.S. National Residue Program (NRP) for Meat, Poultry, and Egg Products, administered by the USDA [U.S. Department of Agriculture] FSIS, is an interagency program designed to identify, rank and test for chemical contaminants in meat, poultry, and egg products. They continue, The NRP requires the cooperation and collaboration of several agencies for its successful design and implementation. The USDA FSIS, the EPA [U.S. Environmental Protection Agency], and the Department of Health and Human Services (DHHS) FDA are the primary federal agencies managing this program. The FDA, under the Federal Food, Drug, and Cosmetic Act, establishes tolerances for veterinary drugs, and action levels for food additives and environmental contaminants. The EPA, under the Federal Insecticide, Fungicide, and Rodenticide Act (as modified by the Food Quality Protection Act), establishes tolerance levels for registered pesticides…. Representatives from FSIS, FDA, EPA, the USDA Agricultural Research Service (ARS), the USDA Agricultural Marketing Service (AMS), and the DHHS Centers for Disease Control and Prevention (CDC) collaborate to develop the scheduled sampling program. Setting and enforcing safety levels involves several steps, one of which is the collection of meat and poultry samples, followed by statistical analysis, interpretation, and action. The NRP sampling plan is designed to identify samples with residues above the allowed levels. The data are then analyzed as categorical values (violation, no violation). Current methods of data analysis do not include estimation of mean values that can then be extrapolated to the national food supply. It was by analyzing the data as a continuous variable that my coauthors and I were able to describe the high levels of arsenic in chicken in 2004 (Lasky et al. 2004). Concerns about arsenic levels in chicken are of increasing importance because of the increased per capita consumption of chicken over the past decade (USDA Economic Research Service 2013).

Oral Argument: Sublingual Findings Challenge Key Assumptions about BPA Exposure

Key assumptions about bisphenol A (BPA) exposure and bioavailability may be off base, according to a new report in EHP that questions the traditional interpretation of biomonitoring data underlying current risk assessments of the chemical.1 Laboratory research suggests that BPA, a widely used chemical for polycarbonate plastics and other products, is an endocrine disruptor with potential adverse health effects involving reproduction, metabolism, and cancer.2,3 Median daily intake of the chemical through the diet is estimated to be 0.01–0.12 µg/kg body weight, based on urinary concentrations of BPA metabolites.4 These metabolites, particularly BPA glucuronide (BPAG), are not biologically active like the parent compound. Nearly all ingested BPA has been thought to be absorbed in the small intestine and rapidly converted to BPAG in the liver prior to bodywide distribution.5,6 Given the estimated daily intake and assumption of rapid conversion, the European Food Safety Authority set a tolerable daily intake of BPA at 0.05 mg/kg.1 However, the current study indicates that BPA can be completely absorbed directly into the bloodstream from the mouth, thus bypassing early rapid metabolism and remaining biologically active for an extended period of time. “Most previous studies have relied on the gavage method, where BPA is distributed directly into the gut,” says Laura Vandenberg, a postdoctoral fellow at the Tufts University Center for Regenerative and Developmental Biology, who was not involved in the study. “This isn’t how food actually enters our bodies. We chew it, move it around in our mouths, and it interacts with numerous surfaces—our tongue, cheeks, etc.—before it enters the stomach.” Gavage studies suggest there should not be detectable levels of unmetabolized BPA in the blood after exposure, yet dozens of other studies report otherwise, she says. The researchers compared the bioavailability of BPA given sublingually (under the tongue) versus intravenously or by gavage. In one experiment 6 dogs received a dose of 5 mg/kg first intravenously, then a week later sublingually either all at once or one drop at a time. In another experiment, conducted in three parts, the same dogs received a dose of 0.05 mg/kg first intravenously, then sublingually, and finally a 20-mg/kg dose delivered by gavage. After each administration, blood samples were collected to measure BPA and BPAG and calculate various parameters such as maximum concentration, time to maximum concentration, and mean residence time.1 BPA was readily absorbed from both the mouth and the gut, but bioavailability throughout the body differed significantly depending on the absorption site. Over the 2 hours following dosing, 5 mg/g and 0.05 mg/kg sublingual BPA yielded ratios of biologically inactive BPAG to biologically active BPA of 1:1–13:1 and 1:1–6:1, respectively, compared with 237:1–634:1 for the dose placed directly in the stomach.1 If confirmed, new findings on sublingual BPA dosing could have important implications for human exposures to BPA. “The sublingual route is a rather well-known route of absorption for those who are involved in the development of drugs but not for those working with contaminants in general and BPA in particular,” says study coauthor Pierre-Louis Toutain, a professor of physiology and therapeutics at the National Veterinary School of Toulouse, France. He says dogs were chosen as the study animals because their oral tissue closely resembles that of humans. The sublingual dosing used in the study may present different conditions from the exposure that occurs while eating or drinking. It also does not reflect potential nonfood exposures from sources such as dust, cigarette filters, thermal papers, and dental sealants that previous research has suggested occur.7 However, “the authors have shown very clearly that when BPA comes into contact with the mucosa under the tongue, it can be rapidly absorbed into the bloodstream. When this happens, it enters the bloodstream without being metabolized,” says Vandenberg. Additionally, this study may explain previous biomonitoring reports of plasma BPA levels deemed impossible or incorrect based on assumptions about gut-only absorption. This is important because plasma levels found in biomonitoring studies are similar to those found to cause adverse health effects in animal studies.7 Urinary BPAG serves as an index of external BPA exposure in biomonitoring studies, but it tells us nothing about the route of absorption, says Toutain. Given the researchers’ findings, he says it would be unacceptable to assume that only a negligible fraction of BPAG circulated as active BPA before it was converted to the inactive form measured in urine. He says, “It is clear that our data suggesting that BPA bioavailability can be high should raise some questions and possibly lead some agencies to reconsider their risk analysis on BPA.”

Infectious Diseases Associated with Livestock Production: Mitigating Future Risks

Humans have traveled with their livestock to the ends of the earth, and animal husbandry has transformed the face of the planet. Even as livestock provide food, these same animals have also introduced humans to new diseases. A study in this month’s EHP argues that, although it is unclear whether the intensification of livestock production will lead to a higher risk of disease emergence and transmission, some important risk factors are certainly present.1 This is especially true in contexts where changes are occurring rapidly, sometimes before regulation can catch up. “Strong regulations can do a lot to mitigate zoonotic risk,” says first author Marco Liverani, a social scientist at the London School of Hygiene & Tropical Medicine. But first, he says, we need to better understand which agricultural and economic practices promote emerging infections, if we are to identify vulnerabilities and develop effective policies to address them. For millennia livestock have shared our abodes and our diseases. The Agricultural Revolution led to the development of larger settlements and denser livestock populations. Infectious diseases that only rarely might have struck small numbers of humans in the past could now spread between animals and large numbers of people. The age of epidemics had begun.2 A 2005 study by Mark Woolhouse and Sonya Gowtage-Sequeria, infectious disease specialists at the University of Edinburgh, found that 58% of the 1,407 diseases known to infect humans were zoonotic—that is, they had originated in animals. Pathogens that could infect both animals and humans made up an even bigger proportion of emerging infectious diseases: 73%.3 “We have very intense contact with livestock. There are plenty of opportunities for the pathogens to cross over,” Woolhouse says. “There is a lot of exchange of diseases between humans and livestock in both directions.” The continued growth of the human population, combined with growing demand for animal protein, has further intensified livestock production. The danger in this, according to Liverani and colleagues, is that some practices associated with intensified production have the potential to increase the risk of zoonoses.1 Take the emergence of Nipah virus, which first appeared in Malaysia in 1999. Epidemiologists revealed that Nipah was a virus that had never been seen in humans, and ultimately traced its origins to a family of large bats known as flying foxes.4 As Malaysia’s population increased dramatically in the late twentieth century,5 farmers began growing mangoes and raising pigs in recently deforested areas. Nipah is naturally found in the fruit-eating flying foxes, which feasted on the mangoes planted by farmers. The pigs ate the mangoes that had fallen to the ground, including those that were contaminated by Nipah-laden bat saliva. The pigs caught the virus from the bats, and the humans caught the virus from the pigs.6 Although zoonotic disease is a potential issue for large industrial farming operations,7 it’s also somewhat easier to regulate these operations, given their resources and commercial status, Liverani says. Backyard farmers like the ones in Malaysia might be exposed to fewer animals, but they tend to have longer, closer contact with the animals that they do have. Close contact between humans and livestock can facilitate the exchange of diseases in both directions. According to Liverani and colleagues, the greatest risk may occur when industrial livestock operations exist alongside small family farms and wildlife populations. Liverani says contacts between livestock and wild animals can result in new pathogens entering intensive production units, where the high concentration of animals can facilitate the amplification and transmission of disease. Although the dangers of zoonoses are real, Ro McFarlane, a veterinary epidemiologist at the Australian National University in Canberra, cautions that these diseases are only one aspect of the interconnected disease risks that exist between humans, livestock, and the environment. “The intensification of food industries has also given rise to diseases that affect food production,” she says, citing another example of this interconnection. “Many of these are not zoonotic, but the effect on human health through food security and livelihoods can also be catastrophic.” McFarlane says the strength of the work by Liverani et al. is that it incorporates socioeconomic and political as well as pathogen- and farm-level risk factors into the discussion about how to manage zoonotic risk from intensive livestock industries. “This is the news,” she says—“we are making progress in doing ‘new science.’”

Asymmetric phthalates—A special case for risk assessment

Phthalic acid diesters are ubiquitously present in the environment due to their intensive use as plasticizers. Human exposure to these contaminants has been proved by determining phthalates and their metabolites in human urine and blood. Particular phthalates with ester chain lengths of C4-C6 possess reprotoxic properties [T. Lovekamp-Swan & B. J. Davis, Environmental Health Perspectives 111 (2003) 139–145]. Asymmetric phthalic acid diesters with “critical” C4–C6 chain lengths have been pre-registered in REACH but information on their human metabolism is scarce. Theoretically, two different monoesters with either “critical” or “uncritical” ester moieties may be formed. Thus, for an adequate assessment of possible health risks of asymmetric phthalic acid esters it is essential to know, which of the monoesters are preferably formed by human metabolism. In order to gain insight into the metabolism of asymmetric phthalates, conversion of 11 asymmetric phthalic acid diesters was investigated by in vitro hydrolysis experiments using rat and human liver S9 homogenates. All asymmetric phthalates were fast hydrolysed into mixtures of both possible monoesters and as consequence; organisms are exposed to mixtures of phthalic acid monoesters. Based on these results, the risk assessment of asymmetric phthalic acid diesters seems to be more complex than that of symmetric phthalates because two different monoesters can be formed. This has implications for the risk assessment and the exposure assessment, as in case of asymmetric phthalic acid diesters with a critical chain length, the same metabolites can be formed which are responsible for the reprotoxic effects of already classified reprotoxic phthalates

The Vision of a Green(er) Scientific Conference

The Vision of a Green(er) Scientific Conference

Volcanic Ash and the Respiratory Immune System - Possible Mechanisms behind Reported Infections

Ash plumes erupting from volcanoes can cause a range of health effects following exposure either to the initial emissions or to deposited material that becomes resuspended days, months, or years later. Researchers from the United States, Iceland, and Australia now report in EHP evidence that exposure to volcanic ash may both foster bacterial growth in the respiratory system and weaken the ability of the immune system to limit that growth, possibly contributing to respiratory infections that have been documented in relation to past eruptions.1 Each year eruptions occur at about 50–70 above-sea locations; eruptions have been documented for about 550 volcanoes in all, and roughly 1,300 have been active at some point in the past 10,000 years.2 Some of this activity generates ash plumes that affect potentially millions of people. Volcanic ash can contain significant quantities of respirable particles of rock, minerals, and volcanic glass, and eruptions also emit hazardous gases such as sulfur dioxide, hydrogen sulfide, hydrochloric acid, and hydrofluoric acid.3 The 20 March 2010 eruption of the Icelandic volcano Eyjafjallajokull (pronounced, roughly, AY-yah-FYET-lah-YOH-kuhl), another larger eruption on 14 April 2010, and ongoing volcanic activity through late May 2011 ejected numerous major ash plumes that spread far and wide. For the current study, the researchers primarily used one sample of this ash that was collected on the ground 15 April 2010 at a location 58 km from the volcano. The ash was composed of a complex mixture of aluminosilicate volcanic glass and minerals including iron, titanium, manganese, zinc, strontium, and barium. The researchers used a ubiquitous and potent opportunistic human bacterium, Pseudomonas aeruginosa,4 to test for possible interaction between ash and this sample infectious agent in primary human airway epithelial cells, primary rat alveolar epithelial cells, and primary human and rat alveolar macrophages. Iron-rich ash from the Eyjafjallajokull eruption spread over thousands of square kilometers. A high-power scanning electron microscopy image shows a smooth-surfaced alveolar macrophage in the process of engulfing (“phagocytizing”) ash particles collected by the authors. The authors conclude that reports of increased respiratory infections following eruptions may reflect an ability of volcanic ash to spur the growth of bacteria as well as interfere with innate immunity. They found a statistically significant increase in growth of the cultured bacteria after ash exposure, possibly due in part to bioavailable iron in the ash. They treated the cultured bacteria with antimicrobial peptides, some with and some without ash included. Bacterial growth was inhibited by the peptides as expected, but less so when ash was included. There was some evidence that ash exposure might impede functions of macrophages including autophagy, bacterial killing ability, and inflammatory responses, but those results didn’t reach statistical significance. However, unlike particles found in cigarette smoke and diesel exhaust, the ash did not kill human airway epithelial cells or rat alveolar epithelial cells nor did it disrupt epithelial cell barrier integrity.1 The study results are “very significant, given there are no current risk assessments or therapeutic interventions in place for avoiding potential respiratory infections following exposure to ash, especially for sensitive groups such as asthmatics, infants, and the elderly,” says Kelly BeruBe, director of the Lung and Particle Research Group at Cardiff University in Wales. But BeruBe cautions that numerous limitations of the study make it premature to apply the findings to real-world human exposures. For instance, the ash sample tested was a mixture of coarse and fine particles collected on the ground rather than from the air at a height typical of inhalation. She says this makes it impossible to determine if the effects were caused by the fine particles in this mixture (a size that has been identified in a wealth of studies as especially harmful). In addition, the cultured human cells tested came from only two people and thus aren’t representative of many important variables such as age, health status, risk behaviors, and area of geographic residence. The study also did not address any possible confounding effects of coexposure to toxic gases emitted during eruptions. Volcanic ash can vary substantially depending on factors such as the geochemistry of the individual volcano, the phase of and distance from the eruption, and the degree of posteruption weathering the ash has undergone. Even for the one sample in this study, the published information was too limited to allow accurate analysis of all its mineralogical characteristics, making the study results “problematic for comparisons with other volcano ash,” says Tim Jones, a senior lecturer in environmental geology at Cardiff University. Nonetheless, he says, “This is certainly a step forward in our understanding of the bioreactivity of volcanic ash.”

Nano GO Consortium—A Team Science Approach to Assess Engineered Nanomaterials: Reliable Assays and Methods

Nano GO Consortium—A Team Science Approach to Assess Engineered Nanomaterials: Reliable Assays and Methods