The unsteady state and inertia of chemical regulation under the US Toxic Substances Control Act.

After 40 years, the 1976 US Toxic Substances Control Act (TSCA) was revised under the Frank R. Lautenberg Chemical Safety for the 21st Century Act. Its original goals of protecting the public from hazardous chemicals were hindered by complex and cumbersome administrative burdens, data limitations, vulnerabilities in risk assessments, and recurring corporate lawsuits. As a result, countless chemicals were entered into commercial use without toxicological information. Few chemicals of the many identified as potential public health threats were regulated or banned. This paper explores the factors that have worked against a comprehensive and rational policy for regulating toxic chemicals and discusses whether the TSCA revisions offer greater public protection against existing and new chemicals.

U.S. Food and Drug Administration's interim reference levels for dietary lead exposure in children and women of childbearing age.

Reducing lead exposure is a public health priority for the US Food and Drug Administration as well as other federal agencies. The goals of this research were to 1) update the maximum daily dietary intake of lead from food, termed an interim reference level (IRL), for children and for women of childbearing age (WOCBA) and 2) to confirm through a literature review that with the exception of neurodevelopment, which was not evaluated here, no adverse effects of lead consistently occur at the blood lead level (BLL) associated with the IRL. Because no safe level of lead exposure has yet been identified for children's health, the IRLs of 3 µg/day for children and 12.5 µg/day for WOCBA were derived from the Centers for Disease Control and Prevention reference value of 5 µg/dL BLL, the level at which public health actions should be initiated. The literature review showed that no adverse effects of lead consistently occurred at the BLL associated with the IRLs (0.5 µg/dL). The IRLs of 3 µg/day for children and 12.5 µg/day for WOCBA should serve as useful benchmarks in evaluating the potential for adverse effects of dietary lead.

EPA's non-targeted analysis collaborative trial (ENTACT): genesis, design, and initial findings.

In August 2015, the US Environmental Protection Agency (EPA) convened a workshop entitled "Advancing non-targeted analyses of xenobiotic chemicals in environmental and biological media." The purpose of the workshop was to bring together the foremost experts in non-targeted analysis (NTA) to discuss the state-of-the-science for generating, interpreting, and exchanging NTA measurement data. During the workshop, participants discussed potential designs for a collaborative project that would use EPA resources, including the ToxCast library of chemical substances, the DSSTox database, and the CompTox Chemicals Dashboard, to evaluate cutting-edge NTA methods. That discussion was the genesis of EPA's Non-Targeted Analysis Collaborative Trial (ENTACT). Nearly 30 laboratories have enrolled in ENTACT and used a variety of chromatography, mass spectrometry, and data processing approaches to characterize ten synthetic chemical mixtures, three standardized media (human serum, house dust, and silicone band) extracts, and thousands of individual substances. Initial results show that nearly all participants have detected and reported more compounds in the mixtures than were intentionally added, with large inter-lab variability in the number of reported compounds. A comparison of gas and liquid chromatography results shows that the majority (45.3%) of correctly identified compounds were detected by only one method and 15.4% of compounds were not identified. Finally, a limited set of true positive identifications indicates substantial differences in observable chemical space when employing disparate separation and ionization techniques as part of NTA workflows. This article describes the genesis of ENTACT, all study methods and materials, and an analysis of results submitted to date. Graphical abstract ᅟ.

Application of qualitative and quantitative uncertainty assessment tools in developing ranges of plausible toxicity values for 2,3,7,8-tetrachlorodibenzo-p-dioxin.

Increasing interest in characterizing risk assessment uncertainty is highlighted by recent recommendations from the National Academy of Sciences. In this paper we demonstrate the utility of applying qualitative and quantitative methods for assessing uncertainty to enhance risk-based decision-making for 2,3,7,8-tetrachlorodibenzo-p-dioxin. The approach involved deconstructing the reference dose (RfD) via evaluation of the different assumptions, options, models and methods associated with derivation of the value, culminating in the development of a plausible range of potential values based on such areas of uncertainty. The results demonstrate that overall RfD uncertainty was high based on limitations in the process for selection (e.g., compliance with inclusion criteria related to internal validity of the co-critical studies, consistency with other studies), external validity (e.g., generalizing findings of acute, high-dose exposure scenarios to the general population), and selection and classification of the point of departure using data from the individual studies (e.g., lack of statistical and clinical significance). Building on sensitivity analyses conducted by the US Environmental Protection Agency in 2012, the resulting estimates of RfD values that account for the uncertainties ranged from ~1.5 to 179 pg/kg/day. It is anticipated that the range of RfDs presented herein, along with the characterization of uncertainties, will improve risk assessments of dioxins and provide important information to risk managers, because reliance on a single toxicity value limits the information needed for making decisions and gives a false sense of precision and accuracy.

Requirements for Notification, Evaluation and Reduction of Lead-Based Paint Hazards in Federally Owned Residential Property and Housing Receiving Federal Assistance; Response to Elevated Blood Lead Levels. Final rule.

This final rule amends HUD's lead-based paint regulations to reduce blood lead levels in children under age six (6) who reside in federally-owned or -assisted pre-1978 housing, formally adopting a revised definition of "elevated blood lead level" (EBLL) in children under the age of six (6), in accordance with Centers for Disease Control and Prevention (CDC) guidance. It also establishes more comprehensive testing and evaluation procedures for the housing where such children reside. This final rule also addresses certain additional elements of the CDC guidance pertaining to assisted housing and makes technical corrections and clarifications. This final rule, which follows HUD's September 1, 2016, proposed rule, takes into consideration public comments submitted in response to the proposed rule.

Machine Versus Man: Can Robotic Mops Clean to Lead Safety Standards?

This study compared the effectiveness of using a commercially available robotic mop versus hand mopping as the second step of the U.S. Department of Housing and Urban Development's recommended three-step vacuum­mop­vacuum process to remove lead dust debris from residential floors. A total of 1,703 floors were cleaned using the robotic mop. Lead dust wipe tests from these floors were compared with 995 lead dust wipe tests for floors cleaned with hand mopping. Analysis of the dust wipes showed that cleaning floors with a robotic mop resulted in a clearance failure rate significantly lower than that obtained by cleaning floors by hand (4.8% versus 10.0%; p < .05). The use of newer technologies like robotic mops can help improve the efficiency and thoroughness of floor-cleaning efforts, as well as decrease costs associated with re-cleaning floors following regulated renovations.

[Chemical pollution of baby food products in the Russian Federation].

One of the main problems of nutrition of children and adolescents is to assess chemical contamination of baby food products and the establishment of the relation with the health of the child population. With the entering different chemical compounds in the body of the child there can be observed disorders of the nervous, urinary, cardiovascular system, gastrointestinal tract, as well as metabolic deteriorations, degenerative processes in parenchymal organs and bone destruction. The aim of the study was to analyze data on chemical contamination of baby food products in the Russian Federation for 2012-2014. The analysis was executed on the data of Federal Information Fund of social and hygienic monitoring of the Russian Federation. There were identified priority pollutants (toxic elements, nitrites, nitrates, nitrosamines, pesticides, hydroxymethylfurfural, mycotoxins) and risk areas (the Lipetsk region, the Krasnodar Territory, the Republic of Adygea, city of Moscow, Tatarstan, the Kabardino-Balkar Republic, the Ryazan region). There are detected contamination levels not exceeding MAC (in the dynamics of the three years offollow up, on average 22%), requiring their hygienic assessment. There were determined the baby food products containing most common occurred chemical contaminants: fruits and vegetables products, canned products, canned meat, cereals, dairy products, liquid and adapted and partially adapted milk formalas. Identified data indicate to a need for further studies of chemical substances in products for children's nutrition in order to establish the causal relationships with a various diseases and the substantiation of methodological approaches to the risk assessment of combined exposure to chemical contaminants in concentrations up to the MPC on health of children, including infants.

[Actual problem of methodology and development of evidence-based health risk assessment associated with chemical exposure].

Paramount problems of the development of the assessment of population health risks associated with the chemical exposure in Russia are considered on the ground of critical analysis of reports devoted to methodological issues of the risk assessment and guidelines published since 2010. Causes of the lack in progress of risk assessment are discussed. The information of executed research revealed the significant retardation number of Russian publications devoted to the evidence-based health risk assessment compare to worldwide trend. The analysis of publications according to evidence-based health risk assessment in Russia in 1998 - 2012 demonstrated methodical problems to be leading to the underestimation of the real risk to population's health. There are demonstrated directions in the renewal of methodology and practice of hygienic standardization on the basis of the risk assessment. The comparative analysis of values of uncertainty factors (modifying factors, conversion factors) used for extrapolation and accepted in different countries and organizations was made. The system of extrapolation coefficients of DNEL (Derive No-Effect Level) is presented. The leading principles of modern toxicology and risk assessment based on strict scientific proofs are showed. Criteria of evidence-based toxicology and risk assessment are presented.Among actual problems which demand their decision there are considered: the assessment of combined action in regulatory toxicology; expansion of spheres of the application of health risk assessment methodology; the improvement ofpreparation and certification of experts in the field of health risk assessment; need of check of dispersion models and their replacement by more modern models; the improvement of exposure assessment with taking into account the international requirements; the assessment of regional exposure factors; expansion of atmospheric air monitoring in all the large cities of Russia.

Polyfluorinated substances in abiotic standard reference materials.

The National Institute of Standards and Technology (NIST) has a wide range of Standard Reference Materials (SRMs) which have values assigned for legacy organic pollutants and toxic elements. Existing SRMs serve as homogenous materials that can be used for method development, method validation, and measurement for contaminants that are now of concern. NIST and multiple groups have been measuring the mass fraction of a group of emerging contaminants, polyfluorinated substances (PFASs), in a variety of SRMs. Here we report levels determined in an interlaboratory comparison of up to 23 PFASs determined in five SRMs: sediment (SRMs 1941b and 1944), house dust (SRM 2585), soil (SRM 2586), and sludge (SRM 2781). Measurements presented show an array of PFASs, with perfluorooctane sulfonate being the most frequently detected. SRMs 1941b, 1944, and 2586 had relatively low concentrations of most PFASs measured while 23 PFASs were at detectable levels in SRM 2585 and most of the PFASs measured were at detectable levels in SRM 2781. The measurements made in this study were used to add values to the Certificates of Analysis for SRMs 2585 and 2781.

Accumulation of metals in three fish species from the Yaounde Municipal Lake in Cameroon.

Metals are dangerous to aquatic organisms and they can bioaccumulate in the food chain and represent risk for humans. In order to appraise their levels in fish species, concentrations of various elements including Na, Mg, K, Ca, Al, Fe, Mn, Cr, Ni, Co, Cd, Cu, Pb, Zn, Ba, and Sr were determined in the muscles and gills of three fish species (Oreochromis niloticus, Sarotherodon galilaeus, and Clarias sp.) which are more fished and consumed in the Yaounde Municipal Lake, Cameroon. According to chemical results of the fish samples analyzed by ICP-AES, the concentrations of metals (mg kg(-1), wet tissues) in those fish tissues varied as follows for the muscle (and gill) Na 1480-3780 (4180-9310), Mg 897-1250 (843-1450), K 9600-18,500 (6020-10,400), Ca 430-3900 (22,200-62,400), Al 8.10-615 (113-951), Fe 12.0-725 (307-1160), Mn 1.61-30.1 (14.3-433), Cr 1.58-267 (0.31-35.4), Ni 0.16-1.85 (1.06-2.82), Co 0.10-0.47 (0.07-0.16), Cd 0.11-0.23 (0.10-0.22), Cu 0.59-5.13 (1.31-5.13), Pb 1.11-5.12 (2.56-5.74), Zn 15.4-47.2 (45.3-69.2), Ba 0.61-51.15 (0.35-83.2), and Sr 2.31-5.74 (2.09-5.75). The results revealed that Na, Ca, Zn, Fe, and Mn were higher concentrated in the gills than in the muscles, while K, Cr, Ni, Co, and Cd were more concentrated in the muscles of the species. In addition, all the elements were bioaccumulated in the fish species and the bioaccumulation factors (BAFs) were decreased in the following order: Cr > Ni > Zn > Al > Ca > Pb > Mn > Ba > K > Fe > Mg > Cu > Na > Sr > Co > Cd. Compared to international standards, Pb, Cd, Cr, Ni, and Zn were over the recommendations of the European Community, WHO, and Norwegian guidance values for human health. Therefore, fishes from the Yaounde Municipal Lake are not advised for human consumption as toxic elements might be taken above the recommended levels.

Biomonitoring Equivalents for benzene.

Biomonitoring Equivalents (BEs) are defined as the concentration or range of concentrations of a chemical or its metabolite in a biological medium (blood, urine, or other medium) that is consistent with an existing health-based exposure guideline such as a reference dose (RfD) or tolerable daily intake (TDI). BE values can be used as a screening tool for the evaluation of population-based biomonitoring data in the context of existing risk assessments. This study reviews available health based risk assessments and exposure guidance values for benzene from the United States Environmental Protection Agency (US EPA), Texas Commission on Environmental Quality (TCEQ), California's Office of Environmental Health Hazard Assessment (OEHHA) and the Agency for Toxic Substances and Disease Registry (ATSDR) to derive BE values for benzene in blood and urine. No BE values were derived for any of the numerous benzene metabolites or hemoglobin and albumin adducts. Using existing physiologically based pharmacokinetic (PBPK) models, government risk assessment values were translated into corresponding benzene levels in blood assuming chronic steady-state exposures. BEs for benzene in urine were derived using measured correlations between benzene in urine with benzene in blood. The BE values for benzene in blood range from 0.04 to 1.29 µg/L, depending upon the underlying non-cancer risk assessment used in deriving the BE. Sources of uncertainty relating to both the basis for the BE values and their use in evaluation of biomonitoring data, including the transience of the biomarkers relative to exposure frequency, are discussed. The BE values derived here can be used as screening tools for evaluation of population biomonitoring data for benzene in the context of the existing risk assessment and can assist in prioritization of the potential need for additional risk assessment efforts for benzene relative to other chemicals.

Defining reference values of trace elements in the tear film: diagnostic methods and possible applications.

The study has been performed on tears of apparently healthy subjects who live and work in urban and rural areas, respectively. After the collection the following elements were investigated: chromium (Cr); arsenic (As); copper (Cu); zinc (Zn); selenium (Se); rubidium (Rb); barium (Ba); lead (Pb) and cobalt (Co). Significantly higher values of As were found in subjects living and working in rural areas as compared to those found in urban area residents (0.290 vs. 0.025; p<0.001). Conversely, Ba and Pb were significantly lower in rural area residents (1.10 vs. 2.50, p=0.027 and 1.70 vs. 1.10, p=0.057, respectively). Our data show that trace elements analysis in tears is possible; further studies could define if it could be a reliable biomarker in persons exposed to high concentration of trace elements due to working or environmental reasons.

Blood plasma clinical-chemical parameters as biomarker endpoints for organohalogen contaminant exposure in Norwegian raptor nestlings.

Raptors are exposed to biomagnifying and toxic organohalogenated compounds (OHCs) such as organochlorines, brominated flame retardants and perfluorinated compounds. To investigate how OHC exposure may affect biochemical pathways we collected blood plasma from Norwegian northern goshawk (n=56), golden eagle (n=12) and white-tailed eagle (n=36) nestlings during three consecutive breeding seasons. We found that blood plasma concentrations of calcium, sodium, creatinine, cholesterol, albumin, total protein, urea, inorganic phosphate, protein:creatinine, urea:creatinine and uric acid:creatinine ratios and liver enzymes ALKP and ALAT were positively correlated to PCBs, chlordanes, p,p'-DDE, HCB, PFCs and/or PBDEs. Total bilirubin and glucose were negatively correlated to PCBs while magnesium and potassium were negatively correlated to HCB and p,p'-DDE. In addition, protein:creatinine and ALAT were also negatively correlated to PCBs and PFCs, respectively. The most significant relationships were found for the highly contaminated northern goshawks and white-tailed eagles. The statistical relationships between OHCs and BCCPs indicate that biochemical pathways could be influenced while it is uncertain if such changes have any health effects. The OHC concentrations were below concentrations causing reproductive toxicity in adults of other raptor species but similar to those of concern for endocrine disruption of thyroid hormones in e.g., bald eagles.

Baseline element composition of foliose and fruticose lichens along the steep climatic gradient of SW Patagonia (Aisén Region, Chile).

Samples of foliose (Nephroma antarcticum) and fruticose (Usnea sp.) lichens were collected across a steep climatic and vegetation gradient in a remote, almost pristine region of SW Chilean Patagonia. Concentrations of major and trace elements in lichens from the rainforest were among the lowest ever reported worldwide for foliose and fruticose lichens and can be considered background levels for the region. The two lichen growth forms showed different elemental compositions mainly due to the greater capacity of foliose thalli to intercept elements from windborne and canopy-leached particles. The patterns of spatial variation in the chemical composition of lichens were effectively explained by statistical methods and reflected the different availability of wet and dry deposition along the steep climatic gradient. Baseline values established for N. antarcticum samples growing in temperate Nothofagus forests were therefore distinct from those of samples growing in more open, drier habitats. The fruticose Usnea sp. showed a higher affinity for atmophile Hg, low concentrations of lithophilic elements, and the same baseline composition whether from temperate forests or from dry, barren environments. The provided background and baseline values against which variations can be measured will be useful in the early detection of local or regional climatic and environmental change, especially in view of the planned construction of hydropower dams under the recently approved HidroAysén Project.

Screening organic chemicals in commerce for emissions in the context of environmental and human exposure.

Quantitative knowledge of organic chemical release into the environment is essential to understand and predict human exposure as well as to develop rational control strategies for any substances of concern. While significant efforts have been invested to characterize and screen organic chemicals for hazardous properties, relatively less effort has been directed toward estimating emissions and hence also risks. Here, a rapid throughput method to estimate emissions of discrete organic chemicals in commerce has been developed, applied and evaluated to support screening studies aimed at ranking and identifying chemicals of potential concern. The method builds upon information in the European Union Technical Guidance Document and utilizes information on quantities in commerce (production and/or import rates), chemical function (use patterns) and physical-chemical properties to estimate emissions to air, soil and water within the OECD for five stages of the chemical life-cycle. The method is applied to 16,029 discrete substances (identified by CAS numbers) from five national and international high production volume lists. As access to consistent input data remains fragmented or even impossible, particular attention is given to estimating, evaluating and discussing uncertainties in the resulting emission scenarios. The uncertainty for individual substances typically spans 3 to 4 orders of magnitude for this initial tier screening method. Information on uncertainties in emissions is useful as any screening or categorization methods which solely rely on threshold values are at risk of leading to a significant number of either false positives or false negatives. A limited evaluation of the screening method's estimates for a sub-set of about 100 substances, compared against independent and more detailed emission scenarios presented in various European Risk Assessment Reports, highlights that up-to-date and accurate information on quantities in commerce as well as a detailed breakdown on chemical function are critically needed for developing more realistic emission scenarios.

Arsenic and lead in juice: apple, citrus, and apple-base.

Exposure limits for arsenic and lead in drinking water have long been established by the U.S. Environmental Protection Agency and new regulations regarding the presence of these contaminants in bottled water went into effect in California in 2009. No comparable exposure limits or regulations are available, however, for juices and other beverages that may contain arsenic and lead. In the study described in this article, 20 apple juices (or ciders), 15 apple-containing juices, one grape, and one citrus juice were analyzed for arsenic and lead. Arsenic was detected in all juices while lead was detected in more than 94% of juices analyzed. Twelve samples (32%) demonstrated arsenic levels nearly at or above the drinking water exposure limit of 10 parts per billion. No juices contained lead above drinking water exposure limits. Expanding drinking water limits to include juices (and other frequently consumed beverages) would better protect consumers while regular testing of these juices would better inform consumers of the risks posed by specific juices and brands.

Contamination of cows milk by heavy metal in Egypt.

The present investigation was carried out to assess the residues levels of five metals (Cadmium, Copper, Lead, Iron and Zinc) in cow milk collected from different sites in El-Qaliubiya governorate, Egypt. A total of 100 cow milk samples were collected from twenty cows in each location sites during the morning milking in the period from March to April, 2011. The highest average concentration are those of iron (16.38 µg/g) followed by zinc (10.75 µg/g) and lead (4.404 µg/g), while the lowest mean concentration are 2.836 and 0.288 µg/g for copper and cadmium, respectively. The results showed that most of the milk samples from the different sites containing all the studied metals with concentration higher than those recommended for milk by international dairy federation standard and Codex.