Environmental Health Implications Research Articles

Degradation of microbial proteins – Molecular-scale understanding of the forms and dynamics of organic nitrogen in soils

Abstract A reliable supply of nitrogen is essential for agricultural productivity, and therefore meeting global food demands. However, the management of nitrogen for sustainable development remains challenging, and this situation is likely to worsen due to the combined effects of land degradation, anthropogenic climate change, and rapid population growth. Furthermore, the escape of reactive nitrogen form agricultural soils has adverse implications for human and environmental health. Therefore, if we are to increase crop productivity whilst mitigating the adverse effects of reactive nitrogen in the environment, it is important to have a detailed molecular-scale understanding of the forms and turnover of nitrogen in soil as a prerequisite to improving global nitrogen-use efficiency. This data article combines the application of High-Resolution Magic Angle Spinning (HR-MAS) NMR spectroscopy and allied analytical approaches to provide molecular-scale understanding of the forms and dynamics of organic nitrogen in soils, using microbial-derived proteins as a surrogate.

Herd-level prevalence of selected endemic infectious diseases of dairy cows in Great Britain

To implement appropriate and effective disease control programs at the national level, up-to-date and unbiased information on disease frequency is needed. The aim of this study was to estimate the prevalence of selected endemic infectious diseases in the population of dairy herds in Great Britain. Bulk milk tank (BMT) samples from 225 randomly selected dairy farms, stratified by region and herd size, were tested for antibodies against bovine viral diarrhea virus (BVDV), bovine herpesvirus type 1, Mycobacterium avium ssp. paratuberculosis, Leptospira Hardjo, Salmonella spp., Coxiella burnetii, Fasciola hepatica, Neospora caninum, and Ostertagia ostertagi. Furthermore, the presence of BVDV, C. burnetii, and Chlamydia-like organisms was determined by PCR. The apparent herd prevalence was estimated as a weighted proportion of positive herds. The true prevalence was calculated when a test was used with known test characteristics for the cut-off value used. Among unvaccinated herds, the true prevalence of BMT antibodies against BVDV was estimated at 66% [95% confidence interval (CI): 56-77%], M. avium ssp. paratuberculosis 68% (95% CI: 59-77%), bovine herpesvirus type 1 62% (95% CI: 52-73%), Leptospira Hardjo 47% (95% CI: 34-60%), and Salmonella spp. 48% (95% CI: 39-56%). The apparent prevalence of BMT antibodies against C. burnetii was 80% (95% CI: 75-85%), F. hepatica 55% (95% CI: 48-62%), N. caninum 46% (95% CI: 38-54%), and O. ostertagi 95% (95% CI: 91-98%). The BVDV, C. burnetii, and Chlamydia-like antigens were detected in 5 (95% CI: 2-9%), 29 (95% CI: 21-36%), and 31% (95% CI: 24-38%) of herds, respectively. Our results show that dairy cows across GB are frequently exposed to the studied pathogens, which are endemic at high levels with some geographical variations. These prevalence estimates provide a much-needed basis to assess whether nationwide control programs for the studied pathogens are justified by their potential economic, environmental, and public health implications. Should surveillance and control programs be initiated, the estimates presented here are a baseline against which progress can be assessed.

Survey on awareness and attitudes of secondary school students regarding plastic pollution: implications for environmental education and public health in Sharjah city, UAE.

Since the industrial revolution in the 1800s, plastic pollution is becoming a global reality. This study aims to assess knowledge and attitude about plastic pollution among secondary school students in Sharjah city, United Arab Emirates. A cross-sectional study was conducted among 400 students in 6 different secondary schools in Sharjah city. Self-administered questionnaires were distributed through probability stratified random sampling method between February and April 2016. Majority of the population understands how harmful plastic wastes are to the environment (85.5%). However, the students' mean knowledge score was 53%, with females (P<0.01), grades 11 and 12 (P=0.024), and students whose mothers were more educated (P=0.014) being more knowledgeable and inclined towards pro-environmental behavior. Yet, all students showed tendency to be involved in the fighting against this dilemma. Strategies which address deficiencies, provide incentives for change, and assure governmental support along with environmental education are needed to bridge the information gap and enhance opportunities to adopt pro-environmental behaviors.

Deforestation and biomass fuel dynamics in Uganda

Forests are, and will remain for decades to come, a critical source of domestic energy for households in East Africa. Deforestation threatens to alter the supply of biomass available to households. We use remote sensing and longitudinal household data to understand the relationship between agriculture-led deforestation and household energy choices in Uganda. Our hypothesis is that rapid deforestation and associated biomass stock depletion affects the type, quantity, and quality of fuels used by households. We analyze land use changes characterizing deforestation and forest degradation at 500-m spatial resolution. Using two waves of survey data for 451 households, we describe changes in the type, quantity, and source of biomass fuels used. We estimate net losses of 4.51 billion kg or 26% of available air-dry biomass over an 8-year period in 5-km buffers surrounding the study villages. We estimate a series of panel mixed-effect regression models to test whether reduction in biomass availability affects fuel choice and find that lower biomass availability is associated with an increase in fuel sourced from non-forest areas, use of crop residues as a cooking fuel, and time to collect fuel. We find that households are transitioning from fuelwood sourced from forests to fuelwood sourced from areas with much less available and lower quality biomass. We find limited evidence that investment in tree planting is replacing natural forests as a source of high quality biomass fuel. Our findings have implications for both human and environmental health particularly in biomass dependent and population dense settings in sub-Saharan Africa.

The Fate of Pollutants in Porous Asphalt Pavements, Laboratory Experiments to Investigate Their Potential to Impact Environmental Health.

Pervious Paving Systems (PPS) are part of a sustainable approach to drainage in which excess surface water is encouraged to infiltrate through their structure, during which potentially toxic elements, such as metals and hydrocarbons are treated by biodegradation and physical entrapment and storage. However, it is not known where in the PPS structure these contaminants accumulate, which has implications for environmental health, particularly during maintenance, as well as consequences for the recycling of material from the PPS at the end-of-life. A 1 m3 porous asphalt (PA) PPS test rig was monitored for 38 months after monthly additions of road sediment (RS) (367.5 g in total) and unused oil (430 mL in total), characteristic of urban loadings, were applied. Using a rainfall simulator, a typical UK rainfall rate of 15 mm/h was used to investigate its efficiency in dealing with contamination. Water quality of the effluent discharged from the rig was found to be suitable for discharge to most environments. On completion of the monitoring, a core was taken down through its surface, and samples of sediment and aggregate were taken. Analysis showed that most of the sediment remained in the surface course, with metal levels lower than the original RS, but higher than clean, unused aggregate or PA. However, even extrapolating these concentrations to 20 years’ worth of in-service use (the projected life of PPS) did not suggest their accumulation would present an environmental pollution risk when carrying out maintenance of the pavement and also indicates that the material could be recycled at end-of-life.

Assessing the sustainability of vegetable production practices in northern Ghana

ABSTRACTUrban vegetable production is an intensive agricultural strategy through which urban dwellers secure income and improve their livelihoods. An ethnographic study was conducted in Tamale, Northern Ghana, to understand whether vegetable gardening was a sustainable form of intensification. The study used an updated version of the Food and Agricultural Organization’s International Framework for Evaluating Sustainable Land Management. Accordingly, qualitative data were collected on the security and access to land, political acceptability and human and environmental health implications of urban patch farming. Changes between 2008 and 2014 in the spatial area of the vegetable sites were measured. Cabbage farmer incomes were quantified. The study found that urbanization has prompted an increase in the cultivation of highly profitable vegetables like cabbage. However, they are irrigated with grey and waste water while eaten raw. This, and the use of pesticides in high dosages, poses health and environmental hazards. Industrial growth has reduced the area of open space urban agriculture by 8.7% between 2008 and 2014. Farmers cope with this by cultivating on interstitial spaces and moving to periurban fringes. There, farmers develop institutional liaisons to gain access to intensification technologies and commercialize their production. This production system is dynamic but not yet sustainable.

Nanofiller Presence Enhances Polycyclic Aromatic Hydrocarbon (PAH) Profile on Nanoparticles Released during Thermal Decomposition of Nano-enabled Thermoplastics: Potential Environmental Health Implications

Nano-enabled products are ultimately destined to reach end-of-life with an important fraction undergoing thermal degradation through waste incineration or accidental fires. Although previous studies have investigated the physicochemical properties of released lifecycle particulate matter (called LCPM) from thermal decomposition of nano-enabled thermoplastics, critical questions about the effect of nanofiller on the chemical composition of LCPM still persist. Here, we investigate the potential nanofiller effects on the profiles of 16 Environmental Protection Agency (EPA)-priority polycyclic aromatic hydrocarbons (PAHs) adsorbed on LCPM from thermal decomposition of nano-enabled thermoplastics. We found that nanofiller presence in thermoplastics significantly enhances not only the total PAH concentration in LCPM but most importantly also the high molecular weight (HMW, 4-6 ring) PAHs that are considerably more toxic than the low molecular weight (LMW, 2-3 ring) PAHs. This nano-specific effect was also confirmed during in vitro cellular toxicological evaluation of LCPM for the case of polyurethane thermoplastic enabled with carbon nanotubes (PU-CNT). LCPM from PU-CNT shows significantly higher cytotoxicity compared to PU which could be attributed to its higher HMW PAH concentration. These findings are crucial and make the case that nanofiller presence in thermoplastics can significantly affect the physicochemical and toxicological properties of LCPM released during thermal decomposition.

Mechanistic study of lead desorption during the leaching process of ion-absorbed rare earths: pH effect and the column experiment.

High concentrations of ammonium sulfate, often used in the in situ mining process, can result in a decrease of pH in the environment and dissolution of rare earth metals. Ammonium sulfate can also cause desorption of toxic heavy metals, leading to environmental and human health implications. In this study, the desorption behavior and fraction changes of lead in the ion-absorbed rare earth ore were studied using batch desorption experiments and column leaching tests. Results from batch desorption experiments showed that the desorption process of lead included fast and slow stages and followed an Elovich model well. The desorption rate and the proportion of lead content in the solution to the total lead in the soil were observed to increase with a decrease in the initial pH of the ammonium sulfate solution. The lead in soil included an acid-extractable fraction, reducible fraction, oxidizable fraction, and a residual fraction, with the predominant fractions being the reducible and acid-extractable fractions. Ninety-six percent of the extractable fraction in soil was desorbed into solution at pH=3.0, and the content of the reducible fraction was observed to initially increase (when pH >4.0) and then decrease (when pH <4.0) with a decrease in pH. Column leaching tests indicated that the content of lead in the different fractions of soil followed the trend of reducible fraction > oxidizable fraction > acid-extractable fraction > residual fraction after the simulating leaching mining process. The change in pH was also found to have a larger influence on the acid-extractable and reducible fractions than the other two fractions. The proportion of the extractable fraction being leached was ca. 86%, and the reducible fraction was enriched along the migration direction of the leaching liquid. These results suggest that certain lead fractions may desorb again and contaminate the environment via acid rain, which provides significant information for environmental assessment and remediation after mining process. Graphical abstract ᅟ.

The Microbiota of Recreational Freshwaters and the Implications for Environmental and Public Health.

The microbial communities in recreational freshwaters play important roles in both environmental and public health perspectives. In this study, the bacterial community structure and its associations with freshwater environments were investigated by analyzing the summertime microbiomes of three beach waters in Ohio (East Fork, Delaware, and Madison lakes) together with environmental and microbial water quality parameters. From the swimming season of 2009, 21 water samples were collected from the three freshwater beaches. From the samples, 110,000 quality-checked bacterial 16S rRNA gene sequences were obtained and analyzed, resulting in an observation of 4500 bacterial operational taxonomic units (OTUs). The most abundant bacteria were Mycobacterium and Arthrobacter of the Actinobacteria (33.2%), Exiguobacterium and Paenisporosarcina of the Firmicutes (23.4%), Planktothrix and Synechococcus of the Cyanobacteria (20.8%), and Methylocystis and Polynucleobacter of the Proteobacteria (16.3%). Considerable spatial and temporal variations were observed in the bacterial community of Actinobacteria, Cyanobacteria, and Firmicutes, where the bacterial community structure was greatly influenced by hydrological and weather conditions. The most influential factors were (1) water inflow for Bacteroidia and Clostridia, (2) turbidity for Gammaproteobacteria, (3) precipitation for Bacilli, and (4) temperature and pH for Cyanobacteria. One noticeable microbial interaction in the bacterial community was a significant negative relationship between Cyanobacteria and Bacilli (P < 0.05). Concerning beach water quality, the level of the genetic markers for cyanobacterial toxin (mcyA) was linked to the abundance of Cyanobacteria. In addition, unique distributions of the genera Enterococcus, Staphylococcus, Streptococcus, Bacteroides, Clostridium, Finegoldia, Burkholderia, and Klebsiella, together with a high density of fecal indicator Escherichia coli, were markedly observed in the sample from Madison Lake on July 13, suggesting a distinctly different source of bacterial loading into the lake, possibly fecal contamination. In conclusion, deep sequencing-based microbial community analysis can provide detailed profiles of bacterial communities and information on potential public health risks at freshwater beaches.

Effects of seasonal meteorological variables on E. coli persistence in livestock faeces and implications for environmental and human health.

Agriculture contributes significant volumes of livestock faeces to land. Understanding how faecal microbes respond to shifts in meteorological patterns of contrasting seasons is important in order to gauge how environmental (and human health) risks may alter under a changing climate. The aim of this study was to: (i) quantify the temporal pattern of E. coli growth within dairy faeces post defecation; and (ii) derive E. coli seasonal population change profiles associated with contrasting environmental drivers. Evaluation of the die-off dynamics of E. coli revealed that a treatment mimicking drought and warming conditions significantly enhanced persistence relative to E. coli in faeces that were exposed to field conditions, and that this pattern was consistent across consecutive years. The internal temperature of faeces was important in driving the rate of change in the E. coli population in the immediate period post defecation, with most E. coli activity (as either die-off or growth) occurring at low dry matter content. This study highlighted that the use of seasonal E. coli persistence profiles should be approached with caution when modelling environmental and human health risks given the increased likelihood of atypical seasonal meteorological variables impacting on E. coli growth and die-off.

Characterization of heavy metals in soils from typical tobacco cultivated areas, China

The heavy metal in tobacco has been widely concerned for the toxicity and bioaccumulation. Heavy metal in tobacco is of extremely related with the corresponding concentration in soil. One hundred soil samples were collected from five typical tobacco cultivated areas to evaluate the environmental quality and health implications. The inductively coupled plasma mass spectrometry was employed to determine the concentrations of heavy metals (As, Cd, Cr, Cu, Hg, and Pb). The geo‐accumulation index and potential health risk assessment were performed to investigate the environmental quality and health risk. The concentrations of As, Cd, Cr, Cu, Hg, and Pb are ranged from 0.40 to 112 mg/kg, 0.07 to 4.22 mg/kg, 5.52 to 338 mg/kg, 3.40 to 64.5 mg/kg, 0 to 1.62 mg/kg, respectively. The concentrations of heavy metals are various among the five different typical cultivation areas. The elevated concentrations of heavy metals in the selected soils suggesting that these heavy metals may be derived from anthropogenic sources i.e. industrial and agricultural activities. The results shown that the soils in the Jingxi, Longlin, and Debao County are posed to a moderately to heavily contamination for Hg and Cd. The noncarcinogenic and carcinogenic effects (except Lingyun County) caused by heavy metal exposure is regarded as acceptable. The Lingyun County soil should be paid more attention due to the unacceptable level of carcinogenic risk. As, Cd, Hg, and Cr are regarded as the priority control metals. © 2016 American Institute of Chemical Engineers Environ Prog, 36: 483–488, 2017

Effects of rare earth elements on the environment and human health: A literature review

REEs are a group of metals comprised of yttrium, fourteen lanthanide elements, and scandium, which have been called ‘industrial vitamins’ and a ‘treasury’ of novel materials due to their dominant role in technical progress and in the development of traditional industries. Despite the growing interest, information that has become available over the last two decades regarding RREs is relatively premature and scarce, which has led to the current controversy regarding the health benefits vs toxic effects of these materials. There are many environmental and health issues associated the production, processing, and utilization of REEs. This review offers an examination of the roles of REEs in the onset of cellular oxidative stress in reference to the impact of REE exposure to cells, animals, and plants, in order to explain disease and occupational poisoning of local residents, water pollution, and farmland destruction. Conversely, a body of evidence has shown REE-associated antioxidant effects in the treatment of many diseases. The content herein is aimed at presenting the recent and pending developments in the field of REE with respect to environmental and human health implications. Multi-faceted updates on the roles of REEs focusing on different organisms and exposure routes, and several issues regarding environmental and biological research, are discussed. The current gaps in information raise a number of open questions that deserve ad hoc investigation.

The effect of Na–Ca–Cl brines on the dissolution of arsenic from arsenopyrite under geologic carbon dioxide storage conditions

Arsenopyrite (FeAsS) is one of the most common mineral sources of arsenic in rocks, sediments, and ores. The dissolution of arsenopyrite releases arsenic, which has potential implications for human and environmental health. With carbon dioxide storage in saline, sedimentary geologic formations being an important component of mitigation strategies for global warming, the effect of injected CO2 mixed with anoxic brines on dissolution of arsenic from arsenopyrite merits examination. Arsenopyrite dissolution was studied using anoxic Na–Ca–Cl brines in the presence and absence of CO2, at both ambient and high temperature and pressure conditions. Results revealed that the dissolution rate of arsenic ranged from 10−10 to 10−12mol/m2s, with an average dissolution rate of 10–10.7±0.2mol/m2s in the absence of CO2. Understanding effects of particular brine constituents on arsenopyrite dissolution requires further investigation, however. The observed arsenopyrite dissolution rates under anoxic conditions are about two orders of magnitude lower than those observed under oxidizing conditions. The presence of dissolved CO2 in brines resulted in dissolution rates marginally lower than those observed in the absence of CO2, with an average dissolution rate of 10–11.2±0.5mol/m2s, even though a reduction in pH to approximately 3.5 was observed. Increase in temperature and pressure from 25°C to 60°C, and 1bar to 100bars respectively, increased As dissolution rate from arsenopyrite by 1logunit.

Exploration, Mining and Energy Generation in Nigeria: Exposure to Organo-Chlorinated Compound and Other Chemicals — Environmental and Public Health Implications

As an oil producing Nation with large mineral deposits, coal is one source of energy generation in Nigeria. However, bye-products of these minerals as alternative energy sources include heavy soot, high emissions of greenhouse gases and resultant organo-contaminates, which are bye-products (i.e., wastes) of heavy machineries. These wastes constitute hazards to the environment and public health. Consequently, Nigeria faces the challenge of organic waste with reverberations and negative impacts on the social, political and economic development of the nation. In this paper we examine the exploration, mining and generation of energy in Nigeria and how the practices involved results in hazards that include exposure to Organo-Chlorinated Compound, Poly-Chlorinated Biphenyl (PCB), classified amongst a group of persistent organic pollutants (POPs). Drawing from empirical data captured, we analyze the environmental and public health implications of PCB and other chemicals such as mercury. Our findings reveal that environmental pollution from POPs and indeed chemical sources have increased in Nigeria, due mainly, to the expansion of urban, agricultural and industrial activities. We conclude by providing recommendations for the management and governance of POPs and address the policy implementations of the findings.

Southwest climate gap: poverty and environmental justice in the US Southwest

ABSTRACTThis article examines the “climate gap” in the Southwest US (Arizona and New Mexico), referring to the “disproportionate and unequal implications of climate change and climate change mitigation” for “people of color and the poor” [Shonkoff, S.B., et al., 2011. The climate gap: environmental health and equity implications of climate change mitigation policies in California. Climatic Change, 109 (Suppl. 1), S485–S503]. The climate and poverty relationship is examined using multi-scaled analysis across three indicators of climate vulnerability, focusing on connections to health, food, and energy during the period 2010–2012. We provide an overview of climate-related social vulnerability in the Southwest based on available federal, state, and county-level census data. We then summarise the results from a stakeholder workshop and in-depth interviews about climate vulnerabilities with social service providers in southern Arizona. We identify a significant Southwest climate gap based on census data and interview findings about climate vulnerability especially relating to high levels of poverty, health disparities, and increasing costs for energy, water, and food. We find that grassroots and community organisations have mobilised to respond to climate and social vulnerability, yet resources for mitigation and adaptation are insufficient given the high level of need. Confronting a changing climate that is projected to be hotter, drier, and with the potential to reach new thresholds, we suggest that more research needs to be done to understand the social and spatial characteristics of climate risk and how low-income populations embody and experience climate risk, and adapt to a changing climate.

The Link between Knowledge, Attitudes and Practices in Relation to Atmospheric Haze Pollution in Peninsular Malaysia.

Transboundary haze episodes caused by seasonal forest fires have become a recurrent phenomenon in Southeast Asia, with serious environmental, economic, and public health implications. Here we present a cross-sectional survey conducted among people in Kuala Lumpur and surrounds to assess the links between knowledge, attitudes, and practices in relation to the transboundary haze episodes. Of 305 respondents, 125 were amateur athletes participating in a duathlon event and the remainder were surveyed in an inner-city shopping mall. Across the whole sample, people who possessed more factual information about the haze phenomenon showed significantly higher levels of concern. Duathletes were more knowledgeable than non-duathletes and also more concerned about the negative effects of haze, especially on health. For all people who regularly practice outdoor sports (including people interviewed at the shopping mall), higher levels of knowledge and concerned attitudes translated into a greater likelihood of engaging in protective practices, such as cancelling their outdoor training sessions, while those with greater knowledge were more likely to check the relevant air pollution index on a daily basis. Our results indicate that the provision of accurate and timely information about air quality to residents will translate into beneficial practices, at least among particularly exposed individuals, such as amateur athletes who regularly practice outdoor sports.

Thermal decomposition of nano-enabled thermoplastics: Possible environmental health and safety implications

Nano-enabled products (NEPs) are currently part of our life prompting for detailed investigation of potential nano-release across their life-cycle. Particularly interesting is their end-of-life thermal decomposition scenario. Here, we examine the thermal decomposition of widely used NEPs, namely thermoplastic nanocomposites, and assess the properties of the byproducts (released aerosol and residual ash) and possible environmental health and safety implications. We focus on establishing a fundamental understanding on the effect of thermal decomposition parameters, such as polymer matrix, nanofiller properties, decomposition temperature, on the properties of byproducts using a recently-developed lab-based experimental integrated platform. Our results indicate that thermoplastic polymer matrix strongly influences size and morphology of released aerosol, while there was minimal but detectable nano-release, especially when inorganic nanofillers were used. The chemical composition of the released aerosol was found not to be strongly influenced by the presence of nanofiller at least for the low, industry-relevant loadings assessed here. Furthermore, the morphology and composition of residual ash was found to be strongly influenced by the presence of nanofiller. The findings presented here on thermal decomposition/incineration of NEPs raise important questions and concerns regarding the potential fate and transport of released engineered nanomaterials in environmental media and potential environmental health and safety implications.

Naturally Occurring Radioactive Materials in Coals and Coal Combustion Residuals in the United States.

The distribution and enrichment of naturally occurring radioactive materials (NORM) in coal combustion residuals (CCRs) from different coal source basins have not been fully characterized in the United States. Here we provide a systematic analysis of the occurrence of NORM ((232)Th, (228)Ra, (238)U, (226)Ra, and (210)Pb) in coals and associated CCRs from the Illinois, Appalachian, and Powder River Basins. Illinois CCRs had the highest total Ra ((228)Ra + (226)Ra = 297 ± 46 Bq/kg) and the lowest (228)Ra/(226)Ra activity ratio (0.31 ± 0.09), followed by Appalachian CCRs (283 ± 34 Bq/kg; 0.67 ± 0.09), and Powder River CCRs (213 ± 21 Bq/kg; 0.79 ± 0.10). Total Ra and (228)Ra/(226)Ra variations in CCRs correspond to the U and Th concentrations and ash contents of their feed coals, and we show that these relationships can be used to predict total NORM concentrations in CCRs. We observed differential NORM volatility during combustion that results in (210)Pb enrichment and (210)Pb/(226)Ra ratios greater than 1 in most fly-ash samples. Overall, total NORM activities in CCRs are 7-10- and 3-5-fold higher than NORM activities in parent coals and average U.S. soil, respectively. This study lays the groundwork for future research related to the environmental and human health implications of CCR disposal and accidental release to the environment in the context of this elevated radioactivity.

Frac Sand Mines Are Preferentially Sited in Unzoned Rural Areas.

Shifting markets can cause unexpected, stochastic changes in rural landscapes that may take local communities by surprise. Preferential siting of new industrial facilities in poor areas or in areas with few regulatory restrictions can have implications for environmental sustainability, human health, and social justice. This study focuses on frac sand mining—the mining of high-quality silica sand used in hydraulic fracturing processes for gas and oil extraction. Frac sand mining gained prominence in the 2000s in the upper midwestern United States where nonmetallic mining is regulated primarily by local zoning. I asked whether frac sand mines were more commonly sited in rural townships without formal zoning regulations or planning processes than in those that undertook zoning and planning before the frac sand boom. I also asked if mine prevalence was correlated with socioeconomic differences across townships. After creating a probability surface to map areas most suitable for frac sand mine occurrence, I developed neutral landscape models from which to compare actual mine distributions in zoned and unzoned areas at three different spatial extents. Mines were significantly clustered in unzoned jurisdictions at the statewide level and in 7 of the 8 counties with at least three frac sand mines and some unzoned land. Subsequent regression analyses showed mine prevalence to be uncorrelated with land value, tax rate, or per capita income, but correlated with remoteness and zoning. The predicted mine count in unzoned townships was over two times higher than that in zoned townships. However, the county with the most mines by far was under a county zoning ordinance, perhaps indicating industry preferences for locations with clear, homogenous rules over patchwork regulation. Rural communities can use the case of frac sand mining as motivation to discuss and plan for sudden land-use predicaments, rather than wait to grapple with unfamiliar legal processes during a period of intense conflict.

Association between prenatal exposure to polybrominated diphenyl ethers and young children's neurodevelopment in China

The use of polybrominated diphenyl ethers (PBDEs) has been dramatically increasing over the last two decades in China. Animal studies suggest that prenatal exposure to PBDEs may result in neurodevelopmental deficits. Two hundred thirty-two participating mothers were recruited from a prospective birth cohort in rural northern China between September 2010 and February 2012. We analyzed 232 cord blood specimens for selected PBDE congeners and examined their association with children's developmental quotients (DQs) at 12 (n=192) and 24 (n=149) months of age based on the Gesell Developmental Schedules (motor, adaptive, language, and social domains). There were no substantial differences by demographic characteristics among the three time points: baseline, 12 and 24 months of age. Median cord blood levels of PBDE congeners 47, 99, 100, and 153 were 3.71, 6.70, 2.63, and 2.19ng/g lipid, respectively. At 12 months of age, neither the individual nor total (the sum of BDEs 47, 99, 100, and 153) congener levels were associated with any of the four domain DQs. However, at 24 months of age, a 10-fold increase in BDE-99 levels was associated with a 2.16-point decrease [95% confidence interval (CI): −4.52, −0.20] in language domain DQs and a 10-fold increase in BDE-47 levels was associated with a 1.89-point decrease (95% CI: −3.75, −0.03) in social domain DQs. Prenatal exposure to PBDEs was associated with lower DQs in young children. The results contribute to the growing evidence that PBDEs could act as developmental neurotoxicants,and the findings have implications for children's environmental health in China.