Agency For Toxic Substances And Disease Registry Research Articles

Investigating the toxic effects of 2-aminoanthracene ingestion in pregnant Sprague Dawley dams

ABSTRACTPolycyclic aromatic hydrocarbons (PAHs) refer to organic compounds that are byproducts of incomplete combustion of fossil fuels and wood. One specific polycyclic aromatic hydrocarbon, 2-aminoanthracene (2AA), is a member of a broader group of compounds known as anthracenes, which have been classified by the United States Agency for Toxic Substances and Disease Registry (ASTDR) as one of a group of PAHs of top concern based on their greater potential risk for exposure and greater harmful effects to humans, compared to other PAHs. Previous research has shown that 2AA affects genes involved in carbohydrate and lipid metabolism, inflammatory stress responses, and immune system responses, among other processes. The objective of the present study was to examine the toxicity of dietary ingestion of 2AA from gestation through the postnatal period. Pregnant dams (Day 1) were purchased from Taconic Hudson, NY, and assigned into dose regimens of 0 mg/kg- (control-C), 50 mg/kg- (low dose-LD) and 100 mg/kg-diet (high dose-HD) 2AA. Dams were fed 2AA contaminated diet during the period of gestation and postpartum. Insulin and H&E immunohistochemical staining were undertaken and indicated no significant changes between control and treated groups. However, percent pancreatic islets (islets within the pancreas) were larger in the exposed groups. The value was 1.5% in the control dams compared to 3.2% and 4.3% low dose and high dose groups respectively. Serum concentrations of albumin and lactate dehydrogenase (LDH) were increased in the exposed groups, with the HD group experiencing the greater increase. Analyses of Fabp4, Mgmt , Fas, Nhej1, Aldh1a1 and Ncam1 were conducted via real-time quantitative polymerase chain reaction (RT-pPCR), using β-Actin as the control gene. There was an up-regulation of the Mgmt and Nhej1 gene transcripts in the exposed groups, with the extent of upregulation being highest in the HD group. Taken together, a link between environmental exposure to 2AA and pancreatic effects appears to exist.

Validation of an analytical methodology to determine polychlorinated biphenyls in samples from blood plasma

Polychlorinated biphenyls are among the five most toxic persistent contaminants for living organisms according to the Agency for Toxic Substances and Disease Registry (ATSDR). To standardize and validate an analytical method to determine and quantify polychlorinated biphenyl indicators in samples from blood plasma by means of gas chromatography-mass spectrometry. We fortified a plasma pool to do the matrix assays. Additionally, we used the NIST SRM® 1958 reference material for the veracity and intermediate accuracy assays. Methodology recovery percentages ranged between 88.4 and 97.5%, and the bias was less than 20%. Detection and quantification limits were 0.04 μg/L and 0.10 μg/L, respectively, for all polychlorinated biphenyl indicators. The linearity represented by the determination coefficient (R2) varied between 0.9866 and 0.9886. Accuracy, expressed as relative standard deviation was less than 20% in all the linear work range (0.5-500 μg/L). Finally, we analyzed 115 samples from Colombian population in various zones of the country and we found 65 positive samples, from which two samples were above HBM-II (7.0 μg/L, 2XΣPCB 138, 153, 180), and two, above HBM-I (3.5 μg/L, 2XΣPCB 138, 153, 180). The method we developed is accurate for PCB analysis in blood plasma samples and could be used for biological surveillance of these contaminants in the Colombian population.

Validación de una metodología analítica para determinar bifenilos policlorados en muestras de plasma sanguíneo

Introduction: Polychlorinated biphenyls are among the five most toxic persistent contaminants for living organisms according to the Agency for Toxic Substances and Disease Registry (ATSDR). Objective: To standardize and validate an analytical method to determine and quantify polychlorinated biphenyl indicators in samples from blood plasma by means of gas chromatography-mass spectrometry. Materials and methods: We fortified a plasma pool to do the matrix assays. Additionally, we used the NIST SRM® 1958 reference material for the veracity and intermediate accuracy assays. Results: Methodology recovery percentages ranged between 88.4 and 97.5%, and the bias was less than 20%. Detection and quantification limits were 0.04 μg/L and 0.10 μg/L, respectively, for all polychlorinated biphenyl indicators. The linearity represented by the determination coefficient (R2) varied between 0.9866 and 0.9886. Accuracy, expressed as relative standard deviation was less than 20% in all the linear work range (0.5-500 μg/L). Finally, we analyzed 115 samples from Colombian population in various zones of the country and we found 65 positive samples, from which two samples were above HBM-II (7.0 μg/L, 2XΣPCB 138, 153, 180), and two, above HBM-I (3.5 μg/L, 2XΣPCB 138, 153, 180). Conclusion: The method we developed is accurate for PCB analysis in blood plasma samples and could be used for biological surveillance of these contaminants in the Colombian population

Minimal Risk Level Derivation for Cadmium: Acute and Intermediate Duration Exposures

The Agency for Toxic Substances and Disease Registry (ATSDR) lists cadmium as one of its priority hazardous substances. The agency conducted a comprehensive literature review of cadmium and used the information to develop a toxicological profile that identified the full range of health effects associated with exposure to cadmium. It included an assessment that identified screening levels, termed health guidance values or minimal risk levels (MRLs), below which adverse health effects are not expected. In this paper, we describe how MRLs for cadmium are derived. For the acute inhalation MRL, the traditional no observed adverse effect level or lowest observed adverse effect level (NOAEL/LOAEL) approach is used; for the oral intermediate MRL, the benchmark dose (BMD) approach is used. MRLs were developed for the most sensitive route-specific end points, other than mortality and cancer that were sufficiently supported and justified by the data. These included an acute duration (1-14 day exposure) inhalation MRL of 0.03 µg Cd/m3 for alveolar histiocytic infiltration and focal inflammation in alveolar septa and an intermediate duration (15-365 day exposure) oral MRL of 0.5 µg Cd/kg/day for decreased bone mineral density.

Contamination levels, toxicity profiles, and emission sources of polycyclic aromatic hydrocarbons (PAHs) in the soils of an emerging industrial town and its environs in the Southeastern Nigeria.

Polycyclic aromatic hydrocarbon (PAH) concentrations in Nnewi and its environs were determined. Soil samples were extracted by sonication using hexane:dichloromethane (3:1) mixture and determined by gas chromatography-flame ionization detection. The total PAHs concentrations (μg/kg) were 16.681 to 46.815, being three orders of magnitude lower than the maximum permissible level recommended by the Agency for Toxic Substances and Disease Registry (ATSDR). These concentrations followed this order: industrial ˃ farmlands ˃ commercial ˃ residential. Industrialized areas showed higher concentrations (p˂0.05) than the other areas. Diagnostic ratios show that the major source of PAHs was the open burning of industrial and agricultural wastes, as shown by the occurrence of highest concentrations in the industrial areas, followed by agricultural areas. Benzo[a]pyrene equivalent values showed non-pollution and very low toxicity. Nevertheless, it was clear that industrialization has had some impact on the PAHs levels in soils and the total environment in this area and could be problematic with time, except with proper environmental management.

Assessment of PCBs and exposure risk to infants in breast milk of primiparae and multiparae mothers in an electronic waste hot spot and non-hot spot areas in Ghana

The aim of the study was to assess the levels of PCBs in the breast milk of some Ghanaian women at suspected hotspot and relatively non-hotspot areas and to find out if the levels of these PCBs pose any risk to the breastfed infants. A total of 128 individual human breast milk were sampled from both primiparae and multiparae mothers. The levels of PCBs in the milk samples were compared. Some of these mothers (105 individuals) work or reside in and around Agbogbloshie (hot-spot), the largest electric and electronic waste dump and recycling site in Accra, Ghana. Others (23 donor mothers) also reside in and around Kwabenya (non-hotspot) which is a mainly residential area without any industrial activities. Samples were analyzed using GC–MS/MS. The total mean levels and range of Σ7PCBs were 3.64ng/glipidwt and ˂LOD–29.20ng/glipidwt, respectively. Mean concentrations from Agbogbloshie (hot-spot area) and Kwabenya (non-hotspot areas) were 4.43ng/glipidwt and 0.03ng/glipidwt, respectively. PCB-28 contributed the highest of 29.5% of the total PCBs in the milk samples, and PCB-101 contributed the lowest of 1.74%. The estimated daily intake of PCBs and total PCBs concentrations in this work were found to be lower as compared to similar studies across the world. The estimated hazard quotient using Health Canada's guidelines threshold limit of 1μg/kgbw/day showed no potential health risk to babies. However, considering minimum tolerable value of 0.03μg/kgbw/day defined by the Agency for Toxic Substances and Disease Registry (ATSDR), the values of some mothers were found to be at the threshold limit. This may indicate a potential health risk to their babies. Mothers with values at the threshold levels of the minimum tolerable limits are those who work or reside in and around the Agbogbloshie e-waste site.

Hurricane Season Public Health Preparedness, Response, and Recovery Guidance for Health Care Providers, Response and Recovery Workers, and Affected Communities - CDC, 2017.

CDC and the Agency for Toxic Substances and Disease Registry (ATSDR) have guidance and technical materials available in both English and Spanish to help communities prepare for hurricanes and floods (Table 1). To help protect the health and safety of the public, responders, and clean-up workers during response and recovery operations from hurricanes and floods, CDC and ATSDR have developed public health guidance and other resources; many are available in both English and Spanish (Table 2).

Manganese testing under a clean air act test rule and the application of resultant data in risk assessments

In the 1990′s, the proposed use of methylcyclopentadienyl manganese tricarbonyl (MMT) as an octane-enhancing gasoline fuel additive led to concerns for potential public health consequences from exposure to manganese (Mn) combustion products in automotive exhaust. After a series of regulatory/legal actions and negotiations, the U.S. Environmental Protection Agency (EPA) issued under Clean Air Act (CAA) section 211(b) an Alternative Tier 2 Test Rule that required development of scientific information intended to help resolve uncertainties in exposure or health risk estimates associated with MMT use. Among the uncertainties identified were: the chemical forms of Mn emitted in automotive exhaust; the relative toxicity of different Mn species; the potential for exposure among sensitive subpopulations including females, the young and elderly; differences in sensitivity between test species and humans; differences between inhalation and oral exposures; and the influence of dose rate and exposure duration on tissue accumulation of Mn. It was anticipated that development of specific sets of pharmacokinetic (PK) information and models regarding Mn could help resolve many of the identified uncertainties and serve as the best foundation for available data integration. The results of the test program included development of several unique Mn datasets, and a series of increasingly sophisticated Mn physiologically-based pharmacokinetic (PBPK) models. These data and models have helped address each of the uncertainties originally identified in the Test Rule. The output from these PBPK models were used by the Agency for Toxic Substances and Disease Registry (ATSDR) in 2012 to inform the selection of uncertainty factors for deriving the manganese Minimum Risk Level (MRL) for chronic exposure durations. The EPA used the MRL in the Agency’s 2015 evaluation of potential residual risks of airborne manganese released from ferroalloys production plants. This resultant set of scientific data and models likely would not exist without the CAA section 211(b) test rule regulatory procedure.

Per- and polyfluoroalkyl substances in human serum and urine samples from a residentially exposed community

BackgroundPer- and polyfluoroalkyl substances (PFAS) are considered chemicals of emerging concern, in part due to their environmental and biological persistence and the potential for widespread human exposure. In 2007, a PFAS manufacturer near Decatur, Alabama notified the United States Environmental Protection Agency (EPA) it had discharged PFAS into a wastewater treatment plant, resulting in environmental contamination and potential exposures to the local community. ObjectivesTo characterize PFAS exposure over time, the Agency for Toxic Substances and Disease Registry (ATSDR) collected blood and urine samples from local residents. MethodsEight PFAS were measured in serum in 2010 (n=153). Eleven PFAS were measured in serum, and five PFAS were measured in urine (n=45) from some of the same residents in 2016. Serum concentrations were compared to nationally representative data and change in serum concentration over time was evaluated. Biological half-lives were estimated for perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), and perfluorohexane sulfonic acid (PFHxS) using a one-compartment pharmacokinetic model. ResultsIn 2010 and 2016, geometric mean PFOA and PFOS serum concentrations were elevated in participants compared to the general U.S. population. In 2016, the geometric mean PFHxS serum concentration was elevated compared to the general U.S. population. Geometric mean serum concentrations of PFOA, PFOS, and perfluorononanoic acid (PFNA) were significantly (p≤0.0001) lower (49%, 53%, and 58%, respectively) in 2016 compared to 2010. Half-lives for PFOA, PFOS, and PFHxS were estimated to be 3.9, 3.3, and 15.5years, respectively. Concentrations of PFOA in serum and urine were highly correlated (r=0.75) in males. ConclusionsSerum concentrations of some PFAS are decreasing in this residentially exposed community, but remain elevated compared to the U.S. general population.

Environmental Health Literacy Promotion Within the TCU Campus Community

An emerging field, environmental health literacy (EHL) aims to equip the public with information and risk communication tools that are applicable and easily understood. This study aimed to determine whether environmental health (EH) education impacts the likelihood of student, faculty, and staff to reduce or stop the use of products that are known to negatively impact health. To address the need for improved EHL, education sessions to promote EHL took place on an urban private university campus among students, faculty, and staff. Students, faculty, and staff on the TCU campus participated in an EH education session. Pender’s (1982) Health Promotion Model and evidence from the Agency for Toxic Substances and Disease Registry (ATSDR) informed session development. 
 Each session consisted of a presentation, hands on demonstration, and group discussion. Participants completed baseline surveys and discussion questions were recorded and transcribed. The investigator used descriptive and content analysis methods to evaluate these data. Twenty-seven participants (17 students, 10 faculty/staff) attended one of five group sessions. Of those, 81.5% reported no prior EH education; however, 77.8% indicated awareness of natural alternatives. An estimated 95% of participants felt the lesson motivated them to make informed choices and educate others. Key barriers to applying EHL in daily life included lack of understanding and education on the topic (37%), cost (33.3%), and brand familiarity (26%). Education sessions promoted EHL among students, faculty, and staff. These sessions have the potential to improve understanding of EH, and the overall health of the community by empowering individuals to make informed choices.

Neurotoxicity of Metal Mixtures.

Metals are the oldest toxins known to humans. Metals differ from other toxic substances in that they are neither created nor destroyed by humans (Casarett and Doull's, Toxicology: the basic science of poisons, 8th edn. McGraw-Hill, London, 2013). Metals are of great importance in our daily life and their frequent use makes their omnipresence and a constant source of human exposure. Metals such as arsenic [As], lead [Pb], mercury [Hg], aluminum [Al] and cadmium [Cd] do not have any specific role in an organism and can be toxic even at low levels. The Substance Priority List of Agency for Toxic Substances and Disease Registry (ATSDR) ranked substances based on a combination of their frequency, toxicity, and potential for human exposure. In this list, As, Pb, Hg, and Cd occupy the first, second, third, and seventh positions, respectively (ATSDR, Priority list of hazardous substances. U.S. Department of Health and Human Services, Public Health Service, Atlanta, 2016). Besides existing individually, these metals are also (or mainly) found as mixtures in various parts of the ecosystem (Cobbina SJ, Chen Y, Zhou Z, Wub X, Feng W, Wang W, Mao G, Xu H, Zhang Z, Wua X, Yang L, Chemosphere 132:79-86, 2015). Interactions among components of a mixture may change toxicokinetics and toxicodynamics (Spurgeon DJ, Jones OAH, Dorne J-L, Svendsen C, Swain S, Stürzenbaum SR, Sci Total Environ 408:3725-3734, 2010) and may result in greater (synergistic) toxicity (Lister LJ, Svendsen C, Wright J, Hooper HL, Spurgeon DJ, Environ Int 37:663-670, 2011). This is particularly worrisome when the components of the mixture individually attack the same organs. On the other hand, metals such as manganese [Mn], iron [Fe], copper [Cu], and zinc [Zn] are essential metals, and their presence in the body below or above homeostatic levels can also lead to disease states (Annangi B, Bonassi S, Marcos R, Hernández A, Mutat Res 770(Pt A):140-161, 2016). Pb, As, Cd, and Hg can induce Fe, Cu, and Zn dyshomeostasis, potentially triggering neurodegenerative disorders, such as Alzheimer's disease (AD) and Parkinson's disease (PD). Additionally, changes in heme synthesis have been associated with neurodegeneration, supported by evidence that a decline in heme levels might explain the age-associated loss of Fe homeostasis (Atamna H, Killile DK, Killile NB, Ames BN, Proc Natl Acad Sci U S A 99(23):14807-14812, 2002).The sources, disposition, transport to the brain, mechanisms of toxicity, and effects in the central nervous system (CNS) and in the hematopoietic system of each one of these metals will be described. More detailed information on Pb, Mn, Al, Hg, Cu, and Zn is available in other chapters. A major focus of the chapter will be on Pb toxicity and its interaction with other metals.

Modeling emissions from CAFO poultry farms in Poland and evaluating potential risk to surrounding populations

The world-wide use of concentrated animal feeding operations (CAFOs) for livestock production demands the need to evaluate the potential impact to public health. We estimated the exposure of various airborne pollutants for populations residing in close proximity to 10 poultry CAFOs located in Central Poland. Ammonia (NH3), carbon dioxide (CO2), carbon monoxide (CO), hydrogen sulfide (H2S), methane (CH4), nitrogen dioxide (NO2), nitrous oxide (N2O), sulfur dioxide (SO2), and organic dust were the pollutants of interest for this study. Because no monitoring data were available, we used the steady-state Gaussian dispersion model AERMOD to estimate pollutant concentrations for the exposed population in order to calculate the hazard index (HI) for a combined mixture of chemicals. Our results indicate that while the levels of certain pollutants are expected to exceed background levels commonly found in the environment they did not result in calculated hazard indexes which exceeded unity suggesting low potential for adverse health effects for the surrounding community for the mixture of chemicals. The study was conducted through a cooperation between the Agency for Toxic Substances and Disease Registry (ATSDR) in the USA and the Nofer Institute of Occupational Medicine (NIOM) in Poland.

GIS based evaluation of fluoride contamination and assessment of fluoride exposure dose in groundwater of a district in Uttar Pradesh, India

ABSTRACTGroundwater is the main source of drinking water in both rural and urban areas of the Pratapgarh district in the eastern Uttar Pradesh. Fifty-five groundwater samples were collected from 17 blocks of the Pratapgarh district and analyzed for fluoride (F−) and other water quality parameters (pH, EC, TDS, turbidity, Cl−, HCO3−, SO42−, NO3−, Ca2+, Mg2+, Na+, K+, silica and total hardness) to assess its suitability for drinking uses. The fluoride concentration in the analyzed groundwater of the Pratapgarh district varied between 0.41 and 3.99 mg/L. Fluoride concentration in about 78% of the groundwater samples exceeded the acceptable level of 1.0 mg/L, while in 70% samples it exceeded the maximum permissible limit of 1.5 mg/L. A geographic information system (GIS) tool was used to study the spatial variation of fluoride concentrations in the groundwater of the Pratapgarh district. Fluoride is positively correlated with pH (0.36) and HCO3− (0.22) and negatively with Ca2+ (−0.23) and Mg2+ (−0.08), suggesting dissolution of fluoride-bearing minerals with the precipitation of Ca/Mg carbonate in the alkaline environment. The maximum exposure dose to fluoride for adults in the study area was found to be 6.8 times higher than the minimum risk level (MRL) of 0.05 mg kg−1 day−1 estimated by the Agency for Toxic Substances and Disease Registry (ATSDR).

Prevalence of Amyotrophic Lateral Sclerosis - United States, 2012-2013.

Amyotrophic lateral sclerosis (ALS), commonly known as Lou Gehrig's disease, is a progressive and fatal neuromuscular disease for which no cure or viable treatment has been identified. ALS, like most noncommunicable diseases, is not a nationally notifiable disease in the United States. The prevalence of ALS in the United States during 2010-2011 was estimated to be 3.9 cases per 100,000 persons in the general population. Updated prevalence estimates are needed to help monitor disease status, better understand etiology, and identify risk factors for ALS. 2012-2013. The National ALS Registry, established in 2009, collects data on ALS patients in the United States to better describe the incidence and prevalence of ALS, examine risk factors such as environmental and occupational exposures, and characterize the demographics of those living with ALS. To identify prevalent cases of ALS, data are compiled from four national administrative databases (maintained by the Centers for Medicare and Medicaid Services, the Veterans Health Administration, and the Veterans Benefits Administration). To identify cases not included in these databases and to better understand risk-factors associated with ALS and disease progression, the Registry also includes data that are collected from patients who voluntarily enroll and complete online surveys. During 2012 and 2013, the Registry identified 14,713 and 15,908 persons, respectively, who met the surveillance case definition of ALS. The estimated ALS prevalence rate was 4.7 cases per 100,000 U.S. population for 2012 and 5.0 per 100,000 for 2013. Due to revisions to the algorithm and use of death data from the National Death Index, an updated prevalence estimate has been calculated retrospectively for October 19, 2010-December 31, 2011. This updated estimate showed a prevalence rate of 4.3 per 100,000 population and a total of 13,282 cases. Since the inception of the Registry, the pattern of characteristics (e.g., age, sex, and race/ethnicity) among persons with ALS have remained unchanged. Overall, ALS was more common among whites, males, and persons aged 60-69 years. The age groups with the lowest number of ALS cases were persons aged 18-39 years and those aged ≥80 years. Males had a higher prevalence rate of ALS than females overall and across all data sources. These findings remained consistent during October 2010-December 2013. The Registry is the only available data source that can be used to estimate the national prevalence for ALS in the United States. Use of both administrative national databases and self-report from patients enables a comprehensive approach to estimate ALS prevalence. The overall increase in the prevalence rate from 4.3 per 100,000 persons (revised) during 2010-2011 to 4.7 and 5.0 per 100,000 persons, respectively, during 2012-2013 likely is not an actual increase in the number of ALS cases. Rather, this increase might be attributed to improved case ascertainment due to the refinement of the algorithm used to identify definite ALS cases, along with an increased public awareness of the Registry. Registry estimates of ALS prevalence are consistent with findings from long-established ALS registries in Europe and from smaller-scale epidemiologic studies previously conducted in the United States. Data collected by the National ALS Registry are being used to better describe the epidemiology of ALS in the United States and to help facilitate research. The combined approach of using national administrative databases and a self-enrollment web portal to collect data is novel and potentially could be used for other non-notifiable diseases such as Parkinson's disease or multiple sclerosis. Increased public awareness of the Registry might lead to more ALS cases being identified from the secure web portal (https://www.cdc.gov/als), which can ascertain cases apart from the national administrative databases. For example, in 2014, the ALS Ice Bucket Challenge, a social media-centered campaign, received extensive public visibility and created increased awareness of ALS. The Agency for Toxic Substances and Disease Registry (ATSDR) works closely with ALS advocacy and support groups, researchers, health care professionals, and others to promote the National ALS Registry and to identify all cases of ALS in the United States. In addition to estimating the prevalence of ALS, the Registry is being used to collect specimens from patient enrollees through a new biorepository, connect patient enrollees with new clinical trials and epidemiologic studies, and fund studies to help learn more about the etiology of ALS. Additional information about the National ALS Registry is available at http://www.cdc.gov/als or by calling toll-free at 1-877-442-9719.

EVALUATING SUSTAINABLE LAND REVITALIZATION PROGRAMS AND POLICIES IN THE UNITED STATES

Since the mid- to late-20 th century, the implementation of land revitalization programs has become much more complex, expensive, and difficult to complete. In the United States, there are four major types of land revitalization programs, which overlap in some areas and clash in others. Over the last few decades, these programs have become increasingly ineffective as their budgets are decreased and the number of sites to focus on increase as well. The Environmental Protection Agency (EPA) oversees the Superfund program, a fund used for environmental cleanup efforts that was established in 1980 with the passage of the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA). The EPA also oversees the National Brownfields Program, which is devoted to revitalizing lands whose redevelopment may be impeded by potential pollution or contamination. The Centers for Disease Control (CDC) oversees the Agency for Toxic Substances Disease Registry (ATSDR), also created under CERCLA. The ATSDR provides risk assessment analysis of Superfund sites and also has its own goals related to brownfield development under its Land/Reuse Action Model. Individual states have enacted their own land revitalization programs, called Voluntary State Programs. Finally, the 2002 revision of the Superfund program sought to devote more resources to brownfield redevelopment, drawing from Voluntary State Programs for private sector incentives. This paper draws upon academic sources and government reports to provide an analysis of these programs and the unintended consequences on local communities which can include displacement from gentrification. Key Words: brownfields programs, bureaucratic behavior, public policy, organizational dynamics, environmental approaches

Toolkit for Epidemiologic Response to an Acute Chemical Release.

When a large chemical incident occurs and people are injured, public health agencies need to be able to provide guidance and respond to questions from the public, the media, and public officials. Because of this urgent need for information to support appropriate public health action, the Agency for Toxic Substances and Disease Registry (ATSDR) of the US Department of Health and Human Services has developed the Assessment of Chemical Exposures (ACE) Toolkit. The ACE Toolkit, available on the ATSDR website, offers materials including surveys, consent forms, databases, and training materials that state and local health personnel can use to rapidly conduct an epidemiologic investigation after a large-scale acute chemical release. All materials are readily adaptable to the many different chemical incident scenarios that may occur and the data needs of the responding agency. An expert ACE team is available to provide technical assistance on site or remotely. (Disaster Med Public Health Preparedness. 2016;10:631-632).

Approaches for describing and communicating overall uncertainty in toxicity characterizations: U.S. Environmental Protection Agency's Integrated Risk Information System (IRIS) as a case study

Single point estimates of human health hazard/toxicity values such as a reference dose (RfD) are generally used in chemical hazard and risk assessment programs for assessing potential risks associated with site- or use-specific exposures. The resulting point estimates are often used by risk managers for regulatory decision-making, including standard setting, determination of emission controls, and mitigation of exposures to chemical substances. Risk managers, as well as stakeholders (interested and affected parties), often have limited information regarding assumptions and uncertainty factors in numerical estimates of both hazards and risks. Further, the use of different approaches for addressing uncertainty, which vary in transparency, can lead to a lack of confidence in the scientific underpinning of regulatory decision-making. The overarching goal of this paper, which was developed from an invited participant workshop, is to offer five approaches for presenting toxicity values in a transparent manner in order to improve the understanding, consideration, and informed use of uncertainty by risk assessors, risk managers, and stakeholders. The five approaches for improving the presentation and communication of uncertainty are described using U.S. Environmental Protection Agency's (EPA's) Integrated Risk Information System (IRIS) as a case study. These approaches will ensure transparency in the documentation, development, and use of toxicity values at EPA, the Agency for Toxic Substances and Disease Registry (ATSDR), and other similar assessment programs in the public and private sector. Further empirical testing will help to inform the approaches that will work best for specific audiences and situations.

Dataset for human sensitivity to chemicals during development of motor function.

The authors reviewed human data related to motor development following exposure to a subset of chemicals thoroughly reviewed in Agency for Toxic Substances and Disease Registry (ATSDR) Toxicological Profiles and Addenda. The resulting dataset includes the following variables and confounders: chemical name, exposure route, exposure duration and frequency, study design, cohort name and/or geographic location, sex of cohort subjects, NOAEL, and LOAEL. This data summary can help validate motor development outcomes observed in animal exposure studies; it can also aid in determining whether these outcomes and corresponding exposure windows are relevant to humans.

Windows of sensitivity to toxic chemicals in the motor effects development

Many chemicals currently used are known to elicit nervous system effects. In addition, approximately 2000 new chemicals introduced annually have not yet undergone neurotoxicity testing. This review concentrated on motor development effects associated with exposure to environmental neurotoxicants to help identify critical windows of exposure and begin to assess data needs based on a subset of chemicals thoroughly reviewed by the Agency for Toxic Substances and Disease Registry (ATSDR) in Toxicological Profiles and Addenda. Multiple windows of sensitivity were identified that differed based on the maturity level of the neurological system at the time of exposure, as well as dose and exposure duration. Similar but distinct windows were found for both motor activity (GD 8–17 [rats], GD 12–14 and PND 3–10 [mice]) and motor function performance (insufficient data for rats, GD 12–17 [mice]). Identifying specific windows of sensitivity in animal studies was hampered by study designs oriented towards detection of neurotoxicity that occurred at any time throughout the developmental process. In conclusion, while this investigation identified some critical exposure windows for motor development effects, it demonstrates a need for more acute duration exposure studies based on neurodevelopmental windows, particularly during the exposure periods identified in this review.

Pediatric Environmental Health Specialty Units: An Analysis of Operations

BackgroundIn 1998 the Agency for Toxic Substances and Disease Registry (ATSDR) secured the first federal funding to develop an innovative network of public health-oriented entities: Pediatric Environmental Health Specialty Units (PEHSUs). PEHSU goals were to provide pediatric and environmental health education to health care providers and health profession students, to offer consultation to health care professionals, parents, and others regarding environmental health exposures, and to provide referrals to specialized medical resources when necessary. This report analyzes the productivity of US PEHSUs from 1999 to 2014. MethodsThis was a retrospective analysis of federally mandated quarterly reports filed by each PEHSU. These reports document specific goal-related deliverables outlined under cooperative agreements awarded to the Association of Occupational and Environmental Clinics (AOEC) with funding from the Environmental Protection Agency (EPA) and ATSDR. Costs were obtained from grant budget information available from the administrator of the grants, AOEC. ResultsTotal EPA/ATSDR funding for PEHSUs paid to AOEC during 1999–2014 was $23,847,452. The average cost to the EPA/ATSDR of running each PEHSU in 2014 was $169,256. Through over 8000 consultations and educational activities, PEHSUs reached 702,506 people: 298,936 health professionals, 61,947 health professional trainees, 323,817 members of the public, and 17,806 public health officials and others. ConclusionsPEHSUs have grown into an established, productive network of clinical and educational centers whose expertise and activities have benefited both the public and health care professionals alike. The federal contributions to the cost of operating these centers have been more than offset by the benefits PEHSUs have conferred on the communities they serve.