Regulatory Guidance Values Research Articles

Risk Control Values and Remediation Goals for Benzo[a]pyrene in Contaminated Sites: Sectoral Characteristics, Temporal Trends, and Empirical Implications.

Benzo[a]pyrene (BaP) is a highly carcinogenic pollutant of global concern. There is a need for a comprehensive assessment of regulation decisions for BaP-contaminated site management. Herein, we present a quantitative evaluation of remediation decisions from 206 contaminated sites throughout China between 2011 and 2021 using the cumulative distribution function (CDF) and related statistical methodologies. Generally, remediation decisions seek to establish remediation goals (RGs) based on the risk control values (RCVs). Cumulative frequency distributions, followed non-normal S-curve, emerged multiple nonrandom clusters. These clusters are consistent with regulatory guidance values (RGVs), of national and local soil levels in China. Additionally, priority interventions for contaminated sites were determined by prioritizing RCVs and identifying differences across industrial sectors. Notably, we found that RCVs and RGs became more relaxed over time, effectively reducing conservation and unsustainable social and economic impacts. The joint probability curve was applied to model decision values, which afforded a generic empirically important RG of 0.57 mg/kg. Overall, these findings will help decision-makers and governments develop appropriate remediation strategies for BaP as a ubiquitous priority pollutant.

Multi-mycotoxin screening of feed and feed raw materials from Africa

As animal feed is prone to infestation with mycotoxin-producing fungi, mycotoxin contamination of feed should be monitored. Here, we report a multi-mycotoxin survey of feed samples from Africa. We determined the concentrations of aflatoxins, fumonisins, deoxynivalenol, T-2 toxin, zearalenone and ochratoxin A in 1,045 samples of finished feed and feed raw materials (maize, maize silage, other cereals, etc.) from South Africa and 318 samples from Algeria, Tunisia, Morocco, Senegal, Côte d’Ivoire, Nigeria, Ghana, Namibia, Uganda, Kenya, Tanzania, Zambia and Madagascar. We compared the measured mycotoxin concentrations to regulatory limits or guidance values that are in effect in the European Union and analysed the co-occurrence of these mycotoxins. To determine the occurrence of other fungal secondary metabolites, a subset of the samples was analysed using a multi-analyte liquid chromatography tandem mass spectrometry-based method for the simultaneous detection of over 700 fungal metabolites. We found that 33.3% of maize samples and 54.4% of finished feed samples from Senegal, Côte d’Ivoire, Nigeria, Ghana, Namibia, Uganda, Kenya and Tanzania exceeded the European regulatory limit of 20 ng/g aflatoxins. TheFusarium mycotoxins zearalenone, fumonisins and deoxynivalenol were prevalent in all commodities from all countries, but concentrations were in most cases below European guidance values. Concentrations of deoxynivalenol and zearalenone were correlated. Several otherFusarium metabolites occurred frequently (e.g. moniliformin, beauvericin, aurofusarin) or in high concentrations (e.g. aurofusarin, fusaproliferin). Furthermore, high levels of diplodiatoxin were occasionally detected in samples from South Africa and theAlternaria metabolite tenuazonic acid was prevalent and reached high concentrations. In conclusion, aflatoxins frequently occurred in African feed samples in potentially unsafe concentrations. WhileFusarium mycotoxins mostly occurred in concentrations below European guidance values, a correlation between deoxynivalenol and zearalenone concentrations suggests that toxicological interactions of these compounds deserve attention. Several less investigated fungal secondary metabolites occurred frequently or reached high concentrations.

A standard-value-based comparison tool to analyze U.S. soil regulations for the top 100 concerned pollutants

Residential surface soil contamination is often addressed by the use of regulatory guidance values (RGVs), which specify the maximum allowed concentration that can be present without prompting a regulatory action. In the U.S., there are at least 72 jurisdictions, including national, state, and regional, that have published guidance values for one or more of the one hundred most frequently regulated chemicals. A standard-value-based comparison tool in this study is developed to analyze values from 40 states and from the U.S. Environmental Protection Agency (U.S. EPA). The comparison tool can help evaluate the completeness of RGV sets, quantify the average deviation of RGVs from worldwide central tendencies, and measure the overall difference between the numbers of RGVs above and below central tendencies. The pollutants considered in this study include benzidines/aromatic amines, dioxins and polychlorinated biphenyls (PCBs), hydrocarbons, inorganic substances, nitroamines/ethers/alcohols, organophosphates and carbamates, pesticides, phenols/phenoxy acids, phthalates, and volatile organic compounds. Based on completeness and comparisons of order of magnitude variations, five types of scores are generated. The results from the completeness scores indicate that some states lack soil RGVs for the top 100 concerned pollutants. The results from the comparison scores indicate that some jurisdictions have provided the RGVs averagely deviating from worldwide central tendencies and U.S. EPA scores by over two orders of magnitude, which might be beyond the risk model variabilities and increase human health risks. Hopefully, the regulatory comparison tool developed in this study will help risk assessors and regulatory scientists to better evaluate soil standards and protect public health.

Worldwide Residential Soil Guidance Values for Total Dioxins and Dioxin-Like Compounds

AbstractDioxins are well-known soil contaminants. Regulatory jurisdictions worldwide use regulatory guidance values (RGV) to help manage dioxin health risks. In the US, seven federal agencies, 41 s...

Variation of United States environmental regulations on pesticide soil standard values

To specify the maximum allowable pesticide concentration in soil, pesticide residential soil regulatory guidance values (RGVs) have been promulgated by U.S. state regulatory jurisdictions to protect human health. A total of 12,451 RGVs for 456 identified pesticides adopted by 46 states were analyzed to evaluate whether there is the agreement among pesticide standard values regulated by the U.S.-related jurisdictions. Among them 62 pesticides with at least 50 RGVs were defined as the commonly regulated pesticides, and seven pesticides with at least 100 RGVs were defined as the most commonly regulated pesticides. A total of 12 states have provided over 500 pesticide soil RGVs and Texas alone has provided at least 1140 RGVs. Results indicate that these pesticide soil RGVs promulgated by the U.S. state jurisdictions for an individual pesticide could vary in a wide range of over six (DDT), seven (alpha-HCH), or even nine (Dieldrin) orders of magnitude. On the other hand, all of the seven most commonly regulated pesticides have a large RGV data cluster in which the state jurisdiction RGVs shared the U.S. Environmental Protection Agency (U.S. EPA) standards. To examine whether those pesticide soil RGVs could protect human health, cancer and non-cancer risk uncertainty bounds were calculated for the seven most commonly regulated pesticides. Results show that for the most commonly regulated pesticides, a total of 265 (41.8% of the total) soil RGVs exceeded the cancer risk uncertainty upper bounds and 30 (4.5% of the total) soil RGVs are above the non-cancer risk uncertainty bounds, which indicates that those RGVs cannot protect human health when exposing to the pesticides from soil.

Health risk characterization of maximum legal exposures for persistent organic pollutant (POP) pesticides in residential soil: An analysis

Regulations for pesticides in soil are important for controlling human health risk; humans can be exposed to pesticides by ingesting soil, inhaling soil dust, and through dermal contact. Previous studies focused on analyses of numerical standard values for pesticides and evaluated the same pesticide using different standards among different jurisdictions. To understand the health consequences associated with pesticide soil standard values, lifetime theoretical maximum contribution and risk characterization factors were used in this study to quantify the severity of damage using disability-adjusted life years (DALYs) under the maximum “legal” exposure to persistent organic pollutant (POP) pesticides that are commonly regulated by the Stockholm Convention. Results show that computed soil characterization factors for some pesticides present lognormal distributions, and some of them have DALY values higher than 1000.0 per million population (e.g., the DALY for dichlorodiphenyltrichloroethane [DDT] is 14,065 in the Netherlands, which exceeds the tolerable risk of uncertainty upper bound of 1380.0 DALYs). Health risk characterization factors computed from national jurisdictions illustrate that values can vary over eight orders of magnitude. Further, the computed characterization factors can vary over four orders of magnitude within the same national jurisdiction. These data indicate that there is little agreement regarding pesticide soil regulatory guidance values (RGVs) among worldwide national jurisdictions or even RGV standard values within the same jurisdiction. Among these POP pesticides, lindane has the lowest median (0.16 DALYs) and geometric mean (0.28 DALYs) risk characterization factors, indicating that worldwide national jurisdictions provide relatively conservative soil RGVs for lindane. In addition, we found that some European nations and members of the former Union of Soviet Socialist Republics share the same pesticide RGVs and data clusters for the computed characterization factors.

Worldwide Regulations of Standard Values of Pesticides for Human Health Risk Control: A Review.

The impact of pesticide residues on human health is a worldwide problem, as human exposure to pesticides can occur through ingestion, inhalation, and dermal contact. Regulatory jurisdictions have promulgated the standard values for pesticides in residential soil, air, drinking water, and agricultural commodity for years. Until now, more than 19,400 pesticide soil regulatory guidance values (RGVs) and 5400 pesticide drinking water maximum concentration levels (MCLs) have been regulated by 54 and 102 nations, respectively. Over 90 nations have provided pesticide agricultural commodity maximum residue limits (MRLs) for at least one of the 12 most commonly consumed agricultural foods. A total of 22 pesticides have been regulated with more than 100 soil RGVs, and 25 pesticides have more than 100 drinking water MCLs. This research indicates that those RGVs and MCLs for an individual pesticide could vary over seven (DDT drinking water MCLs), eight (Lindane soil RGVs), or even nine (Dieldrin soil RGVs) orders of magnitude. Human health risk uncertainty bounds and the implied total exposure mass burden model were applied to analyze the most commonly regulated and used pesticides for human health risk control. For the top 27 commonly regulated pesticides in soil, there are at least 300 RGVs (8% of the total) that are above all of the computed upper bounds for human health risk uncertainty. For the top 29 most-commonly regulated pesticides in drinking water, at least 172 drinking water MCLs (5% of the total) exceed the computed upper bounds for human health risk uncertainty; while for the 14 most widely used pesticides, there are at least 310 computed implied dose limits (28.0% of the total) that are above the acceptable daily intake values. The results show that some worldwide standard values were not derived conservatively enough to avoid human health risk by the pesticides, and that some values were not computed comprehensively by considering all major human exposure pathways.

Worldwide Surface-Soil Polychlorinated Biphenyl Regulatory Guidance Values

AbstractPolychlorinated biphenyls (PCBs) are a family of synthetic chlorinated organic compounds that were manufactured in huge quantities and used worldwide in numerous commercial and industrial a...

Worldwide Regulatory Guidance Values Applied to Direct Contact Surface Soil Pesticide Contamination: Part II—Noncarcinogenic Pesticides

Surface soil regulatory guidance values (RGVs) are available worldwide for nearly 800 pesticides. Part I of this study examined values applied to commonly used carcinogenic pesticides. Part II examines RGVs applied to 12 commonly used noncarcinogenic pesticides: 2,4-D, carbaryl, carbofuran, chlorpyrifos, diazinon, dicamba, diuron, glyphosate, malathion, MCPA, metolachlor, and picloram. The RGVs applied by 38 nations vary by as much as 9.3 orders of magnitude, but the RGV distributions do not fit the lognormal random variable model as well as those reported for other contaminants, and there are value clusters in each distribution. The largest clusters contain values similar to current or previous US Environmental Protection Agency, Australian national, and former USSR values. Because these pesticides are used worldwide, it is important that their RGVs protect human health. Analysis indicates that this goal has not yet been achieved for chlorpyrifos and MCPA.

Worldwide Regulatory Guidance Values Applied to Direct Contact Surface Soil Pesticide Contamination: Part I—Carcinogenic Pesticides

Regulatory agencies worldwide have developed regulatory guidance values (RGVs) for nearly 800 pesticides. Analysis of the residential surface soil guidance values applied to the most frequently regulated current-use agriculture, home, and garden pesticides is presented. Part I concentrates on values applied to atrazine, simazine, and trifluralin. These are unique among commonly used pesticides because they are generally considered to be human carcinogens. Their use has been banned in much of the world, but they are commonly used in the United States. Regulatory guidance values applied to these 3 pesticides vary by 8.6, 5.5, and 5.1 orders of magnitude. Risk model coefficient–bounded set uncertainty analysis is applied to help analyze this variability. Cancer risk model uncertainty bounds appear to contain 36.3%, 43.0%, and 49.5% of the RGVs. Most of the remaining values appear to exceed a lifetime cancer incidence risk of 1 × 10−6 and may not be adequately protective of human health.

Ranking system for national regulatory jurisdictions based on pesticide standard values in major exposures

To control the risk of human exposure to pesticides, about 50 nations have promulgated pesticide soil regulatory guidance values (RGVs), and 104 nations have provided pesticide drinking water maximum concentration levels (MCLs). In addition, 90 nations have regulated pesticide agricultural commodity maximum residue limits (MRLs). Pesticide standard values (PSVs) for one single pesticide varied in a range of six, seven, or even eight orders of magnitude. Some PSVs are too large to prevent the impact of pesticides on human health. Many nations have not provided PSVs for some commonly used pesticides until now. This research has introduced several completeness values and numerical values methods to evaluate the national jurisdiction’s performance on PSVs on a nation base. The national jurisdiction ranking system developed by these methods will be beneficial to the environmental regulation makers in the management of PSVs. Results also indicate that European countries perform better in the regulation of pesticide soil RGVs, drinking water MCLs, and agricultural commodity MRLs.

Residential surface soil guidance values applied worldwide to the original 2001 Stockholm Convention POP pesticides

Surface soil contamination is a worldwide problem. Many regulatory jurisdictions attempt to control human exposures with regulatory guidance values (RGVs) that specify a soil's maximum allowable concentration. Pesticides are important soil contaminants because of their intentional toxicity and widespread surface soil application. Worldwide, at least 174 regulatory jurisdictions from 54 United Nations member states have published more than 19,400 pesticide RGVs for at least 739 chemically unique pesticides. This manuscript examines the variability of the guidance values that are applied worldwide to the original 2001 Stockholm Convention persistent organic pollutants (POP) pesticides (Aldrin, Chlordane, DDT, Dieldrin, Endrin, Heptachlor, Mirex, and Toxaphene) for which at least 1667 RGVs have been promulgated. Results indicate that the spans of the RGVs applied to each of these pesticides vary from 6.1 orders of magnitude for Toxaphene to 10.0 orders of magnitude for Mirex. The distribution of values across these value spans resembles the distribution of lognormal random variables, but also contain non-random value clusters. Approximately 40% of all the POP RGVs fall within uncertainty bounds computed from the U.S. Environmental Protection Agency (USEPA) RGV cancer risk model. Another 22% of the values fall within uncertainty bounds computed from the USEPA's non-cancer risk model, but the cancer risk calculations yield the binding (lowest) value for all POP pesticides except Endrin. The results presented emphasize the continued need to rationalize the RGVs applied worldwide to important soil contaminants.

Analysis of regulatory guidance values for six commonly regulated chlorophenols

Regulatory guidance values (RGVs) are developed by regulators to protect human health by establishing maximum allowable contaminant concentrations. Contamination of residential surface soil is of particular concern because of its potential impact on the general population, especially children. As part of an ongoing examination of soil RGVs, this study analyses guidance values applied to chlorophenols, a class of chemicals used as pesticides, herbicides, and disinfectants. Chlorophenol RGVs have been promulgated by at least 45 US states, 38 United Nations member states, four Native American tribes, five federal agencies, and several city, county, and territorial jurisdictions. An analysis of the six most commonly regulated chlorophenols (2-chlorophenol, 2,4-dichlorophenol, 2,4,5-trichlorophenol, 2,4,6-trichlorophenol, 2,3,4,6-tetrachlorophenol, and pentachlorophenol) demonstrates that there is great variability in the guidance values, which vary by six to eight orders of magnitude and have distributions similar to those of lognormal random variables. Clearly, there is little universal agreement on the appropriate maximum contamination levels for chlorophenols.

Scope of the worldwide effort to regulate pesticide contamination in surface soils

Regulating surface soil contamination is a worldwide problem. Many jurisdictions address this problem with regulatory guidance values (RGVs) that specify the maximum allowable soil concentration of contaminants. Pesticides are a particularly important class of soil contaminants because of their intentional toxicity and widespread application to home, garden, and agricultural soils. Pesticides are also difficult to regulate because they are marketed in thousands of products made from hundreds of potentially toxic chemicals. Worldwide, at least 174 jurisdictions from 54 United Nations member states have promulgated more than 19,400 pesticide RGVs. Values may be found for at least 739 pesticides, identified by unique Chemical Abstract Service numbers (CAS No.). Using CAS numbers helps to avoid confusion that may result from alternative product names, chemical nomenclature conventions, or flawed translations. Assembling the set of pesticide RGVs required translating guidance documents authored in 30 different languages. Results indicate that more than 100 RGVs have been promulgated for each of the 22 most frequently regulated pesticides including over 300 values for DDT. Data are presented on the number of pesticides typically addressed by a regulatory jurisdiction and on the size and variability of the RGV datasets for the 200 most frequently regulated pesticides.

Analysis of worldwide Regulatory Guidance Values for less frequently regulated elemental surface soil contaminants

Guidance values are used to regulate exposure to surface soil contamination. In the United States, element guidance values have been promulgated by at least 6 federal agencies, 46 states, and several regional, city, county, territorial, and autonomous Native American jurisdictions. Guidance values have also been promulgated in at least 74 other United Nations member states. A companion manuscript examined the values applied to the eight most frequently regulated elements (Pb, Cd, As, Ni, Cr, Hg, Cu, and Zn) each for which there are at least 300 guidance values. This manuscript extends analysis to the second tier of contaminants (Sb, Ba, Be, Co, F, Mn, Mo, Se, Ag, Tl, Sn, and V) each for which there are at least 100 guidance values. These values span from 3.4 (for Sn) to 6.1 (for Be) orders of magnitude. Their distributions resemble those of lognormal random variables, but also contain non-random value clusters. On average, with the exception of cobalt, the values used in the U.S. are higher (less conservative) than those used elsewhere. Only about 44% of U.S. values and 31% of all values fall within uncertainty bounds computed for the U.S. Environmental Protection Agency health risk model applied to the elements considered.

The importance of solid-phase distribution on the oral bioaccessibility of Ni and Cr in soils overlying Palaeogene basalt lavas, Northern Ireland

Potentially toxic elements (PTEs) including nickel and chromium are often present in soils overlying basalt at concentrations above regulatory guidance values due to the presence of these elements in underlying geology. Oral bioaccessibility testing allows the risk posed by PTEs to human health to be assessed; however, bioaccessibility is controlled by factors including mineralogy, particle size, solid-phase speciation and encapsulation. X-ray diffraction was used to characterise the mineralogy of 12 soil samples overlying Palaeogene basalt lavas in Northern Ireland, and non-specific sequential extraction coupled with chemometric analysis was used to determine the distribution of elements amongst soil components in 3 of these samples. The data obtained were related to total concentration and oral bioaccessible concentration to determine whether a relationship exists between the overall concentrations of PTEs, their bioaccessibility and the soils mineralogy and geochemistry. Gastric phase bioaccessible fraction (BAF%) ranged from 0.4 to 5.4% for chromium in soils overlying basalt and bioaccessible and total chromium concentrations are positively correlated. In contrast, the range of gastric phase BAF for nickel was greater (1.4-43.8%), while no significant correlation was observed between bioaccessible and total nickel concentrations. However, nickel BAF was inversely correlated with total concentration. Solid-phase fractionation information showed that bioaccessible nickel was associated with calcium carbonate, aluminium oxide, iron oxide and clay-related components, while bioaccessible chromium was associated with clay-related components. This suggests that weathering significantly affects nickel bioaccessibility, but does not have the same effect on the bioaccessibility of chromium.

Analysis of worldwide regulatory guidance values for the most commonly regulated elemental surface soil contamination

Guidance values are used worldwide to regulate exposure to surface soil contamination. This analysis examines values applied to element contamination. In the United States, element guidance values have been promulgated by at least 6 federal agencies, 46 states and several regional, city, county, territorial, and autonomous Native American jurisdictions. Guidance values have also been promulgated in at least 71 other United Nations member states. A total of 5949 guidance values for 57 elements have been identified. These values are characterized, and detailed analyses are provided for the eight most frequently regulated elements (Pb, Cd, As, Ni, Cr, Hg, Cu, and Zn). More than 300 guidance values available for each of these are tabulated. These values span from 3.6 orders of magnitude for lead to 6.9 orders of magnitude for arsenic and are distributed in patterns that resemble those of lognormal random variables. However, nonrandom value clusters are also identified in each distribution. On average, the values used in the U.S. are higher than those used elsewhere around the world for noncarcinogenic contaminants, but are lower for carcinogenic contaminants. Approximately 31.4% of all values fall within uncertainty bounds computed from the U.S. Environmental Protection Agency cancer or noncancer risk model, but only 12.9% of carcinogenic arsenic and 7.5% of carcinogenic chromium (Cr-VI) guidance values fall within cancer risk model uncertainty bounds.

Worldwide regulatory guidance values for surface soil exposure to carcinogenic or mutagenic polycyclic aromatic hydrocarbons

Regulatory guidance values are used worldwide to control residential exposure to surface soil contamination. A total of 1,991 values used in 44 United Nations member states plus 4 territories or administrative regions to control exposure to seven polycyclic aromatic hydrocarbons (PAH) generally considered to be carcinogenic or mutagenic (benz(a)anthracene, benzo(a)pyrene, benzo(b)fluoranthene, benzo(k)fluoranthene, dibenzo(a,h)anthracene, chrysene and indeno(1,2,3-c,d)pyrene) are examined. The distributions of these values vary over 6.3–7.2 orders of magnitude and resemble the distributions of lognormal random variables. The U.S. Environmental Protection Agency (USEPA) values fall near the low end of these distributions and exert a modest influence on the values from other U.S. jurisdictions. On average, 17 additional jurisdictions use USEPA values and 21% of all guidance values fall within uncertainty bounds approximated from the USEPA risk model. An average of 62% of U.S. guidance values fall below the median value, but this varies from 43% for chrysene to 70% for dibenz(a,h)anthracene and benzo(a)pyrene. Although the magnitudes of guidance values differ, the ratios of values often reflect the relationships implied by benzo(a)pyrene Toxicity Equivalency Factors (TEFs). This influence is strongest in RGVs from U.S. jurisdictions.

Analysis of Worldwide Naphthalene Surface Soil Regulatory Guidance Values

Many environmental regulatory jurisdictions worldwide specify the maximum soil contamination mass burdens that may occur without prompting a regulatory response. For residential surface soils, these regulatory guidance values (RGVs) are generally based on human (often child) health risks from inhalation, ingestion, and dermal exposure to contamination. RGVs have been promulgated for more than 1,200 soil contaminants. Of these, naphthalene is the most frequently regulated contaminant. The 234 known naphthalene RGVs range from a minimum of 0.0289 mg/kg to a maximum of 16,000 mg/kg and span 5.7 orders of magnitude. Analysis illustrates that, although there are small non-random clusters of values, and there may be statistically significant differences between the values used in the U.S. and elsewhere around the world, the overall distribution of numbers strongly resembles (r = 0.9953) that of a log-normal random variable. Results of Monte Carlo uncertainty analysis applied to the U.S. Environmental Protection Agency risk model are presented to approximate the range of the naphthalene RGV span that can be attributed to uncertainty in cancer or non-cancer risk formulations. Uncertainty in the cancer risk formulation could account for approximately 41% of the RGVs. Uncertainty in the non-cancer risk formulation could account for a different 22% of the RGVs, but the cancer risk model generally yields the binding (lowest) value. The implications of these widely variable RGVs for health risk and remediation costs are discussed and methods of reducing variability are suggested.

Worldwide Regulatory Guidance Values for Chlorinated Benzene Surface Soil Contamination

AbstractSurface soil contamination is a worldwide problem that is often addressed by the use of regulatory guidance values (RGVs) that establish the maximum amount of contamination that may exist without prompting a regulatory response. Chlorinated benzenes are a family of 12 synthetic aromatic contaminants for which at least 168 jurisdictions have promulgated guidance values. Analysis of the 973 RGVs for the eight most commonly regulated chlorinated benzenes is presented. The RGVs of chlorobenzene, 1,2-, 1,3- and 1,4-diclorobenzene, 1,2,4-trichlorobenzene, 1,2,4,5-tetrachlorobenzene, and hexachlorobenzene vary by over six orders of magnitude. The RGVs for pentachlorobenzene vary by five orders of magnitude. The RGV distributions resemble those of lognormal random variables, but contain nonrandom clusters and extreme values that deviate from the lognormal distribution model. Point clusters appear to reflect the influence of organizations such as the U.S. Environmental Protection Agency (USEPA) and the Can...