Integrated Risk Information System Research Articles

Health Risk Assessment of Nitrate Contamination in Groundwater: A Case Study of an Agricultural Area in Northeast China

High levels of nitrates in groundwater pose a risk to human health. In this study, we selected areas with typical agricultural nitrate pollution in northeast China as study sites. We then collected groundwater samples for nitrate nitrogen content analysis using the Four Step method developed by the United State Environmental Protection Agency (USEPA) in conjunction with the non-carcinogens health risk model (R = CDI/RfD) to determine the health risk associated with nitrate pollution of groundwater. The reference value of nitrates in drinking water was set at 10 mg/L (measured as nitrogen) and the intake reference dose of nitrate was set at 1.6 mg•kg−1•d−1 based on the EPA’s IRIS(Integrated Risk Information System). The water intake reference values were set at 2.3 L/d and 1.5 L/d based on the EPA values and actual values observed in the study area. The average exposure time was the ED (exposure duration) × 365d/a. Weights refer to the 2002 national urban and rural average weight of residents of different genders and different ages. Health hazard index calculation was based on the above information, and the index less than 1 is acceptable (U.S. EPA’s Risk Assessment Guide). Health risk assessment maps were then drawn by Arcgis software. The results indicated that agricultural sewage irrigation areas in the study area showed strong health risks, but that those of the city were relatively small. Moreover, the results indicated that children’s health risks are greater than those of adults.

Human health effects of trichloroethylene: key findings and scientific issues.

Background: In support of the Integrated Risk Information System (IRIS), the U.S. Environmental Protection Agency (EPA) completed a toxicological review of trichloroethylene (TCE) in September 2011, which was the result of an effort spanning > 20 years.Objectives: We summarized the key findings and scientific issues regarding the human health effects of TCE in the U.S. EPA’s toxicological review.Methods: In this assessment we synthesized and characterized thousands of epidemiologic, experimental animal, and mechanistic studies, and addressed several key scientific issues through modeling of TCE toxicokinetics, meta-analyses of epidemiologic studies, and analyses of mechanistic data.Discussion: Toxicokinetic modeling aided in characterizing the toxicological role of the complex metabolism and multiple metabolites of TCE. Meta-analyses of the epidemiologic data strongly supported the conclusions that TCE causes kidney cancer in humans and that TCE may also cause liver cancer and non-Hodgkin lymphoma. Mechanistic analyses support a key role for mutagenicity in TCE-induced kidney carcinogenicity. Recent evidence from studies in both humans and experimental animals point to the involvement of TCE exposure in autoimmune disease and hypersensitivity. Recent avian and in vitro mechanistic studies provided biological plausibility that TCE plays a role in developmental cardiac toxicity, the subject of substantial debate due to mixed results from epidemiologic and rodent studies.Conclusions: TCE is carcinogenic to humans by all routes of exposure and poses a potential human health hazard for noncancer toxicity to the central nervous system, kidney, liver, immune system, male reproductive system, and the developing embryo/fetus.

Progress and Pollution: Port Cities Prepare for the Panama Canal Expansion

Early in the planning of the Panama Canal, Navy Commander Thomas Oliver Selfridge, Jr., wrote that “advantageous as an interoceanic canal would be to the commercial welfare of the whole world, it is doubly so for the necessities of American interests.”1 And indeed, since the Canal opened in 1914, it has been the main conduit for ocean-going ships carrying trade worldwide. Today the United States ranks number one in tons of cargo passing through the Canal (China ranks number two).2 In 2011 nearly 13,000 ocean-going cargo ships made the passage.3 Starting in the late 1950s (and expanding rapidly thereafter), internationally traded goods started being shipped in large metal containers, making it possible to load and unload cargo by machine instead of by hand and spurring the manufacture of larger ships.4 “Panamax” ships were designed to be just small enough to squeeze through the locks of the Canal.5 Today, even larger ships—called “post-Panamax” because they are too large to fit through the Canal6—make up 16% of the world’s container fleet but account for nearly half the fleet’s cargo capacity.7 To allow these larger ships to transit the Canal and increase its ability to handle higher volumes of ships, Panama is building a third set of locks, with construction expected to be finished in 2015.7 The Panama Canal expansion has sparked the competitive imagination of East Coast and Gulf Coast (EC/GC) port authorities, who hope to capture some of the 70% of U.S. imports currently controlled by West Coast (WC) ports.8 Ports typically make their revenues through leases with shipping lines, wharfage fees, and tariffs. So the more containers a port handles, the more money it can make. Experts at the U.S. Army Corps of Engineers (USACE) call the Panama Canal expansion a likely “game changer” for U.S. trade, potentially redistributing the market share of each coast’s ports, as well as opening up new import and export markets for agricultural and other products along inland waterways.7 Some have estimated that container volumes at EC/GC ports could more than double from 2012 to 2029.7 But with this growth come questions about what major initiatives to expand cargo capacity could mean for public health in these port cities.

Particulate matter concentrations and their related metal toxicity in rural residential environment of semi-arid region of India

The concentration of PM10, PM5.0, PM2.5 and PM1 were measured in the indoor–outdoor environment of rural homes of North central part of India during winter, summer and rainy seasons for the time duration of October 2007 to March 2009. Seven trace metals (Pb, Cd, Ni, Fe, Cr, Mn and Cu) were also determined in PM2.5 from October 2007 to March 2009 in the indoor–outdoor environment. During the study period the annual average concentration for PM10, PM5.0, PM2.5 and PM1 in indoor and outdoor were 242.53 μg m−3 and 217.76 μg m−3, 203.57 μg m−3 and 180.42 μg m−3, 164.60 μg m−3 and 143.07 μg m−3, 106.23 μg m−3 and 105.17 μg m−3 respectively. Concentrations of PM10 and PM2.5 have been compared with prescribed WHO standards and NAAQS standards of India and were found to be much higher. Significant seasonal variations of particulate pollutants were obtained using the monthly average concentration of coarse and fine particulate matter. Indoor/outdoor ratios at the rural sites were also determined with the meteorological parameters like temperature, humidity, wind speed and air exchange rate. Chromium was found to have the highest excess cancer risk in a risk evaluation using an Integrated Risk Information System. Three factors each in indoor and outdoor environment of rural site have been identified using Principal Component Analysis & Positive Matrix Factorization.

Putative Mechanisms of Environmental Chemical–Induced Steatosis

Liver disease is a major health issue characterized by several pathological changes, with steatosis (fatty liver) representing a common initial step in its pathogenesis. Steatosis is of critical importance because prevention of fatty liver can obviate downstream pathologies of liver disease (eg, fibrosis). Recent studies have shown a strong correlation between chemical exposure and steatosis. The work described here identifies chemicals on the US Environmental Protection Agency's Integrated Risk Information System (IRIS) that induce steatosis and investigates putative mechanisms by which these chemicals may contribute to this pathological condition. Mitochondrial impairment, insulin resistance, impaired hepatic lipid secretion, and enhanced cytokine production were identified as potential mechanisms that could contribute to steatosis. Taken together, this work is significant because it identifies multiple mechanisms by which environmental chemicals may cause fatty liver and expands our knowledge of the possible role of environmental chemical exposure in the induction and progression of liver disease.

석면함유 건축물의 석면 노출 및 위해성 평가

This study was performed to evaluate the asbestos exposure levels and to calculate excess lifetime cacer risks(ELCRs) in asbestos-containing buildings for maintenance and management. The range of airborne asbestos concentration of 33 buildings was 0.0018 ~ 0.0126 f/cc and one site exceeded indoor air-quality recommended limit 0.01 f/cc. And ELCRs based on US EPA IRIS(Integrated risk information system) model are 1.5E-06 ~ 3.9E-05 levels, and there was no site showed 1.0E-04 (one person per million) level or more, and 11 sites showed 1.0E-05 (one person per 100,000 people) level or more. To prevent the release of asbestos fibers, it needs operation and maintenance of asbestos-containing building materials, and there are some methods such as removal, repairment, enclosure and encapsulation. In conclusion, a risk-based air action level for asbestos in air is an appropriate metric for asbestos-containing building management.

Policy: Environmental Protection Agency to seek early input on chemical assessments

In a major change to its criticized chemicals assessment program, EPA will seek early input about chemicals under review. Stakeholders from industry and other concerned groups will be able to provide their views about a substance’s toxicity before EPA decides what information to rely on for the assessments, according to the agency. Kenneth Olden, director of EPA’s National Center for Environmental Assessment, announced the change last week before a new committee of the National Research Council. NRC is reviewing the agency’s chemical hazard assessment database—called the Integrated Risk Information System (IRIS)—for Congress. EPA’s completed IRIS assessments provide scientifically based judgments on the safe dose of a chemical, which is the maximum exposure to the substance that won’t cause health effects. EPA, other federal and state agencies, and some foreign countries use IRIS to guide regulation. With early input from stakeholders, EPA can work with outside parties to pinpoint gaps in ...

A Look at State‐Level Risk Assessment in the United States: Making Decisions in the Absence of Federal Risk Values

State environmental agencies in the United States are charged with making risk management decisions that protect public health and the environment while managing limited technical, financial, and human resources. Meanwhile, the federal risk assessment community that provides risk assessment guidance to state agencies is challenged by the rapid growth of the global chemical inventory. When chemical toxicity profiles are unavailable on the U.S. Environmental Protection Agency's Integrated Risk Information System or other federal resources, each state agency must act independently to identify and select appropriate chemical risk values for application in human health risk assessment. This practice can lead to broad interstate variation in the toxicity values selected for any one chemical. Within this context, this article describes the decision-making process and resources used by the federal government and individual U.S. states. The risk management of trichloroethylene (TCE) in the United States is presented as a case study to demonstrate the need for a collaborative approach among U.S. states toward identification and selection of chemical risk values while awaiting federal risk values to be set. The regulatory experience with TCE is contrasted with collaborative risk science models, such as the European Union's efforts in risk assessment harmonization. Finally, we introduce State Environmental Agency Risk Collaboration for Harmonization, a free online interactive tool designed to help to create a collaborative network among state agencies to provide a vehicle for efficiently sharing information and resources, and for the advancement of harmonization in risk values used among U.S. states when federal guidance is unavailable.

Effects of in vivo chronic exposure to pendimethalin/Prowl 400® on sanitary status and the immune system in rainbow trout (Oncorhynchus mykiss)

The in vivo effects of the herbicide active substance (AS) pendimethalin (alone and with Prowl 400® adjuvant) were evaluated on sanitary status i.e. the health status with regard to chemical pollution and on the physiological state via the immune system in rainbow trout, Oncorhynchus mykiss. Four nominal exposure conditions were tested: i) control (C), ii) AS at 500ngL−1 (P500), iii) AS at 800ngL−1 (P800) and iv) Prowl 400® at 500ngL−1 (Pw). After a 28day exposure period (D28), 10 fish were sampled for each condition and 10 other after a 15day recovery period in clean fresh water (D43). Pendimethalin concentrations in the exposure water and muscles were followed. White blood cell counts, differential leucocyte counts, cell mortality and phagocytosis activity were measured. Haemolytic alternative complement activity, lysozyme concentration and stress parameters were analyzed.The resulting concentration of pendimethalin in the exposure water was lower than the expected concentration. At D28, the concentration quantified in the contaminated fish was negligible in comparison with the Reference Dose for Oral Exposure estimated by US-EPA's Integrated Risk Information System. Leucopenia was noted in all contaminated fish. A decrease in phagocytosis activity and ACH50 was also observed in contaminated fish by P800 and Pw. Disturbed lysozyme activity was noted only in fish exposed to Pw. Furthermore, during exposure to a similar concentration of pendimethalin, the commercial product seemed to be more immunotoxic than the AS alone. Finally, at D43, the effects proved reversible for sanitary status while immunity was still disturbed in contaminated fish by P800 and Pw.

FDA Risk Assessment of Seafood Contamination after the BP Oil Spill: Rotkin-Ellman and Solomon Respond

FDA Risk Assessment of Seafood Contamination after the BP Oil Spill: Rotkin-Ellman and Solomon Respond

Airborne trace metals from coal combustion in Beijing

Prior studies have measured elevated ambient concentrations of hazardous metals in Beijing, attributable to coal combustion. The 2008 Olympic Games led to an intense investment in air pollution controls at the major power plants in the region, accounting for 30% of coal combustion in Beijing. Recently Chinese coal beds have been characterized in the World Coal Quality Index, facilitating the development of trace metal emission factors for Beijing coals. This study quantifies the relative value of the power plant air pollution controls in terms of public health risk from chronic exposure to trace metals. Ambient concentrations from power plants were estimated using an atmospheric dispersion model (CALPUFF), outlining spatial and temporal variations. The following toxic, refractory metals were evaluated for health risk using the USEPA Integrated Risk Information System: antimony, arsenic, beryllium, cadmium, chromium, cobalt, copper, lead, manganese, nickel, and selenium. Stringent use of power plant air pollution controls significantly reduces population risk, averting a cancer risk of 1 in 5,000. However, other sources of coal combustion, such as industrial and household uses, are more relevant to public health than power plant emissions. Coal washing has potential to reduce the hazard from these diffuse sources and avert a greater number of potential cancer cases.

Is industry influencing carcinogen assessments in the USA?

Chemical manufacturers and some US lawmakers are demanding dramatic reforms and increased external scrutiny of the Environmental Protection Agency's (EPA's) chemical carcinogenicity and toxicity assessment programme, known as the Integrated Risk Information System (IRIS), but these would hinder identification of chemical threats to public health, IRIS proponents told The Lancet Oncology.

A Study in Balance: How Microbiomes Are Changing the Shape of Environmental Health

The agents we now know as bacteria have been known for centuries to play a key role in certain kinds of illnesses and ailments. But aside from infectious diseases, the communities of microbes we carry in specific parts of our bodies—our microbiomes—are a relatively new topic in human health. Now this field of study has taken an evolutionary leap forward with new research showing human microbiomes may play a far greater role in environ-mental health than ever imagined. The excitement around this field was obvious at a National Academy of Sciences (NAS) workshop on the interplay of the microbiomes, environ-mental agents, and human health held 27–28 April 2011,1 where talks by researchers working in this area inspired numerous “eureka!” moments. New findings about the ways in which human microbiomes transform arsenic and mercury—two of our most prevalent and well-defined external human health hazards—suggest the role of commensal bacteria may equal or exceed that of genetic polymorphisms that regulate metal transformations within the body, says Ellen Silbergeld, a professor of environmental health sciences at the Johns Hopkins University Bloomberg School of Public Health. The implications of these new insights are staggering. Environmental health scientists may need to expand the toxicokinetics of metals and other environmental agents, as well as associated biomarkers, to include the microbial component. “This is a huge thing that has never been thought of before in environmental health sciences,” Silbergeld told workshop attendees. Emerging findings also demand a re-examination of what it means to be exposed to environmental agents, Silbergeld says. To a toxicologist, she explains, a contaminant is only “in the body” once it has crossed from the external environment into circulating blood, or a cell, or an organ. But new findings suggest biologically relevant transformations may take place prior to absorption, when contaminants interact with the microbiome in the mouth, intestines, or other tissues. Because of the metabolic processes mediated by microbiomes, a great deal of what toxicologists attribute to human metabolism—such as methylation of arsenic—may actually take place at least in part before contaminants cross into the internal environment of our bodies.

Effects of in vivo chronic hydrocarbons pollution on sanitary status and immune system in sea bass ( Dicentrarchus labrax L.)

Following the development of an experimental system to expose adult fish to low and stable concentration of pollutant over a prolonged period, the in vivo effects of hydrocarbons on sanitary status, i.e. the health status of fish with regard to chemical pollution, and immune system in sea bass, Dicentrarchus labrax were assessed. A total of 90 fish were acclimated for 15 days, then 45 fish were exposed to the water soluble fraction (WSF) of Arabian crude oil, similar to a complex pollution by hydrocarbons chronically observed in situ in estuaries, while the 45 other control fish sustained the same experimental conditions in clean seawater. After 21 days of exposure, 30 contaminated and control fish were sampled, then 30 other fish were collected after a 15 day recovery period in clean sea water. PAH concentrations in crude oil, WSF, muscles and bile were measured by gas chromatography coupled with mass spectrometry analysis. White blood cell counts and differential leucocyte counts were determined by classical haematology methods. Cell mortality and phagocytosis activity of leucocytes were analyzed by flow cytometry. Haemolytic alternative complement activity and stress parameters were analyzed in blood plasma by spectrophotometry. After a 21 day exposure period to a mixture of 41 parent/alkylated-PAHs (835 ± 52/85 ± 15 ng L −1). Fish flesh was contaminated by a bioconcentration of naphthalene very closed to the Reference Dose for Oral Exposure estimated by US-EPA's Integrated Risk Information System, causing a potential risk for human consumers. A leucopenia due to a lymphopenia, a rise in leucocyte mortality and a decrease in phagocytosis activity were noted in contaminated fish compared to controls. All these results may be explained by the damage to membrane cells integrity by uptake of PAHs and suggested an impairment of specific and nonspecific immune systems. After a 15 day recovery period, effects were reversible for sanitary status and an offset in immunity was noted by a significant increase in leucocytes in contaminated fish compared to controls.

GIS 기법을 이용한 폐석면 광산의 위해성 평가

폐석면 광산의 위해성 평가는 통상 ABS 방식에 의해 이루어지지만, 조사지역 전반에 관한 위해성 경향을 파악하는 데 그치는 한계를 지닌다. 이 연구에서는 새로운 평가방식으로 잠재적 위해지수(PIHR)라는 개념을 도입하여 석면 위해도를 계랑화하였다. PIHR 값에 대해 석면이 인체에 위해를 주는 요인들을 고려하여 적절한 가중치를 부여한 후, 토양 내 석면 농도 값을 적용하여 지리정보시스템(GIS)의 적지선정기법을 활용하여 위해성 평가를 실시하였다. 충청남도 보령시에 위치한 어느 폐석면 광산에 적용한 결과, 잠재적 위해 지수가 매우 높은 지역은 전체 면적의 7.8%에 해당되는 27.3 ha이며, 위해성 평가는 미국 환경보호청의 종합위해정보시스템(IRIS) 모델을 적용하여 각각 만 명당 1명(석면농도 0.36% 이상), 3만 명당 1명(석면농도 0.1% 이상), 10만 명당 1명(석면농도 0.04% 이상) 평생초과 발암 위험도 기준으로 관리할 경우 3.0, 12.9, 19.5 ha로 면적이 증가한다. 이러한 결과는 향후 광해 복원범위 선정에 효과적으로 적용할 수 있다. Health risk assessments for the abandoned asbestos mine were usually performed with activity-based sampling (ABS) method, which was not a effective tool for indexing health risk on an exact small area of mine. A newly proposed potential index of health risk (PIHR) was applied with proper spatial determination of geographical information system (GIS) to assess quantitatively health risks. A new trial was applied to a certain abandoned mine in Boryong as follows: A high grade area of PIHR was estimated 7.8% of the whole area of the mine (about 27.3 ha). Based on US EPA IRIS (integrated risk information system) model considering lifetime excess cancer risk (LECR), the health risk assessment indicated that the high grade area increased from 3.0 ha through 12.9 ha to 19.5 ha with an increase of asbestos contents in soil from 0.36% (1E-04 level) through 0.1% (3E-05 level) to 0.04% (1E-05 level). These results can be effectively applied to determine reclamation area of the abandoned asbestos mine.

Leveraging Epidemiology to Improve Risk Assessment.

The field of environmental public health is at an important crossroad. Our current biomonitoring efforts document widespread exposure to a host of chemicals for which toxicity information is lacking. At the same time, advances in the fields of genomics, proteomics, metabolomics, genetics and epigenetics are yielding volumes of data at a rapid pace. Our ability to detect chemicals in biological and environmental media has far outpaced our ability to interpret their health relevance, and as a result, the environmental risk paradigm, in its current state, is antiquated and ill-equipped to make the best use of these new data. In light of new scientific developments and the pressing need to characterize the public health burdens of chemicals, it is imperative to reinvigorate the use of environmental epidemiology in chemical risk assessment. Two case studies of chemical assessments from the Environmental Protection Agency Integrated Risk Information System database are presented to illustrate opportunities where epidemiologic data could have been used in place of experimental animal data in dose-response assessment, or where different approaches, techniques, or studies could have been employed to better utilize existing epidemiologic evidence. Based on the case studies and what can be learned from recent scientific advances and improved approaches to utilizing human data for dose-response estimation, recommendations are provided for the disciplines of epidemiology and risk assessment for enhancing the role of epidemiologic data in hazard identification and dose-response assessment.

Development of quantitative structure–activity relationship (QSAR) models to predict the carcinogenic potency of chemicals. II. Using oral slope factor as a measure of carcinogenic potency

The overall risk associated with exposure to a chemical is determined by combining quantitative estimates of exposure to the chemical with their known health effects. For chemicals that cause carcinogenicity, oral slope factors (OSFs) and inhalation unit risks are used to quantitatively estimate the carcinogenic potency or the risk associated with exposure to the chemical by oral or inhalation route, respectively. Frequently, there is a lack of animal or human studies in the literature to determine OSFs. This study aims to circumvent this problem by developing quantitative structure–activity relationship (QSAR) models to predict the OSFs of chemicals. The OSFs of 70 chemicals based on male/female human, rat, and mouse bioassay data were obtained from the United States Environmental Protection Agency’s Integrated Risk Information System (IRIS) database. A global QSAR model that considered all 70 chemicals as well as species and/or sex-specific QSARs were developed in this study. Study results indicate that the species and sex-specific QSARs (r2>0.8, q2>0.7) had a better predictive abilities than the global QSAR developed using data from all species and sexes (r2=0.77, q2=0.73). The QSARs developed in this study were externally validated, and demonstrated reasonable predictive abilities.

Characteristics of particulate matter and metals in the ambient air from a residential area in the largest industrial city in Korea

This study investigated the characteristics of mass size distributions and metallic elements in the airborne particulate matter from an urban, residential area in Ulsan, Korea. Daily PM samples were trapped on glass fiber filters from April to August 2008 using an eight-stage cascade impactor. The identified concentrations of PM1.0, PM2.5 and PM10 were 18.5, 27.6 and 50.5μg/m3, respectively. Light metals (Na, K, Ca, Mg, Al) and two heavy metals (Fe and Zn) were detected in high concentrations in the coarse particles, while the remaining heavy metals (Cd, Cr, Cu, Ni, Mn and Pb) were found mainly in the fine particles. The crustal elements were found in higher concentrations in the spring and the anthropogenic elements were found in high concentrations in the summer. Chromium was found to have the highest excess cancer risk in a risk evaluation using an Integrated Risk Information System. In the results of an analysis of the enrichment factors, Cd, Pb, Cu and Zn were found to be very highly enriched, and Cr and Ni were found to be highly enriched. Factor analysis permitted the identification of three source groups (dust and vehicle exhaust, Cu smelting and oil combustion) for the fine particles and two source groups (industrial emissions and crustal traffic sources) for coarse particles.

Theoretical risk assessment of magnesium alloys as degradable biomedical implants

The theoretical tolerable implant masses for ten magnesium alloys as degradable biomedical implant materials are evaluated in this study. Dose–response assessment is conducted using toxicological data from authoritative public health agencies such as the US Agency for Toxic Substances and Disease Registry and the USEPA Integrated Risk Information System, and assuming 1 year of even corrosion. Uncertainty factors adopted by the agencies are used. The tolerable limits corresponding to various component elements in an alloy are considered separately, and the lowest tolerable limit is selected as the tolerable limit of the alloy. The results show that aluminum is usually the component element with the lowest tolerance, and the tolerable mass for Al-containing magnesium alloys fall to around or below 1 g per person per year, while the limit for other magnesium alloys can well exceed 10 g. Deficits in the toxicological data of some component elements are noted. This study illustrates that toxicological calculations should be taken into consideration when developing novel degradable metallic implants.

Chromium nitrate as a source of chromium added for nutritional purposes to food supplements

Chromium nitrate as a source of chromium added for nutritional purposes to food supplements