Estimating the health benefits of environmental regulations

Reducing uncertainty in dose-response assessments by incorporating Bayesian benchmark dose modeling and in vitro data on population variability

There are two primary sources of uncertainty in the interpretability of toxicity values, like the reference dose (RfD): estimates of the point of departure (POD) and the absence of chemical-specific human variability data. We hypothesize two solutions-employing Bayesian benchmark dose (BBMD) modeling to refine POD determination and combining high-throughput toxicokinetic modeling with population-based toxicodynamic in vitro data to characterize chemical-specific variability. These hypotheses were tested by deriving refined probabilistic estimates for human doses corresponding to a specific effect size (M) in the Ith population percentile (HDM I) across 19 Superfund priority chemicals. HDM I values were further converted to biomonitoring equivalents in blood and urine for benchmarking against human data. Compared to deterministic default-based RfDs, HDM I values were generally more protective, particularly influenced by chemical-specific data on interindividual variability. Incorporating chemical-specific in vitro data improved precision in probabilistic RfDs, with a median 1.4-fold reduction in uncertainty variance. Comparison with US Environmental Protection Agency's Exposure Forecasting exposure predictions and biomonitoring data from the National Health and Nutrition Examination Survey identified chemicals with margins of exposure nearing or below one. Overall, to mitigate uncertainty in regulatory toxicity values and guide chemical risk management, BBMD modeling and chemical-specific population-based human in vitro data are essential.

An Approach to Assessing the Influence of Environmental and Occupational Cancer Hazard Identification on Policy Decision-Making

BACKGROUND

Cancer hazard identification is critical to informing decisions on preventive actions. However, the influence of cancer hazard assessments on the creation of health-protective regulations is poorly understood. Although prior studies have measured the health and economic benefits of regulatory actions in general, we are not aware of efforts to explicitly study the influence of cancer hazard identification on policy decisions in the United States.

OBJECTIVES

In this commentary, we present an approach to examine whether formal identification of a substance as a human carcinogen may prompt a regulatory action to reduce exposure to carcinogens and enhance public health. Further, we discuss the broader implications of cancer hazard identification on policy decision-making, including identifying gaps and providing recommendations.

METHODS

Using the Report on Carcinogens (RoC) as a test case, we systematically searched U.S. federal and state databases for notices of regulations mentioning the RoC from 1995 to 2023. For each regulation, we extracted information on the carcinogen(s) regulated, the regulatory agency, the regulatory purpose, the economic sector exposure sources, and the analyzed public health benefits and costs. We created a publicly available, web-based interactive tool to visualize the data.

DISCUSSION

U.S. regulatory agencies have been using cancer hazard evaluations, such as the RoC, for decades to inform public health policy actions to prevent or mitigate cancer risks. Specifically, nonregulatory cancer hazard assessments have been used to prioritize chemical evaluations, support regulatory-based assessments, and trigger regulatory action. Our approach showed that assessing the influence of cancer hazard identification on science-based public health policies is feasible, informative, and needed, and our study is a first step in this direction. We recommend expanding this approach to other cancer and noncancer hazard assessments to ultimately inform our understanding of the influence of hazard classifications on policymaking. https://doi.org/10.1289/EHP12681.

A better cost:benefit analysis yields better and fairer results: EPA's lead and copper rule revision

When conducted on a societal level, cost-benefit analysis (CBA) can indicate policies that best allocate scarce public resources. Done incompletely, CBA can produce spurious, biased results. To estimate the potential health benefits of EPA's recent Lead and Copper Drinking Water Rule Revision (LCRR), we used EPA's exposure, compliance, and effect coefficient estimates to monetize 16 of the health endpoints EPA has determined are causally related to lead exposure. In addition, we monetized one health endpoint that EPA has used elsewhere: preterm birth. We estimated that the total annual health benefits of the LCRR greatly exceed EPA's estimated annual costs: $9 billion vs $335 million (2016$). Our benefit estimates greatly exceed EPA's benefit estimates. There are also nonhealth benefits because lead generally contaminates drinking water through the corrosion of plumbing components that contain lead. The LCRR therefore has 2 components: reducing how corrosive the water is and limited replacement of lead pipes. Reducing corrosion damage to drinking water and wastewater infrastructure and residential appliances that use water yields significant annualized material benefits also: $2-8 billion (2016$). Effectively, the health benefits are free. Finally, while actual exposure data are limited, the available data on lead-contaminated drinking water exhibits known risk patterns, disproportionately burdening low-income and minority populations and women. This economic analysis demonstrates that to maximize national benefits and improve equity, the LCRR should be as rigorous as possible.

A science-based agenda for health-protective chemical assessments and decisions: overview and consensus statement

The manufacture and production of industrial chemicals continues to increase, with hundreds of thousands of chemicals and chemical mixtures used worldwide, leading to widespread population exposures and resultant health impacts. Low-wealth communities and communities of color often bear disproportionate burdens of exposure and impact; all compounded by regulatory delays to the detriment of public health. Multiple authoritative bodies and scientific consensus groups have called for actions to prevent harmful exposures via improved policy approaches. We worked across multiple disciplines to develop consensus recommendations for health-protective, scientific approaches to reduce harmful chemical exposures, which can be applied to current US policies governing industrial chemicals and environmental pollutants. This consensus identifies five principles and scientific recommendations for improving how agencies like the US Environmental Protection Agency (EPA) approach and conduct hazard and risk assessment and risk management analyses: (1) the financial burden of data generation for any given chemical on (or to be introduced to) the market should be on the chemical producers that benefit from their production and use; (2) lack of data does not equate to lack of hazard, exposure, or risk; (3) populations at greater risk, including those that are more susceptible or more highly exposed, must be better identified and protected to account for their real-world risks; (4) hazard and risk assessments should not assume existence of a "safe" or "no-risk" level of chemical exposure in the diverse general population; and (5) hazard and risk assessments must evaluate and account for financial conflicts of interest in the body of evidence. While many of these recommendations focus specifically on the EPA, they are general principles for environmental health that could be adopted by any agency or entity engaged in exposure, hazard, and risk assessment. We also detail recommendations for four priority areas in companion papers (exposure assessment methods, human variability assessment, methods for quantifying non-cancer health outcomes, and a framework for defining chemical classes). These recommendations constitute key steps for improved evidence-based environmental health decision-making and public health protection.

Conducting evaluations of evidence that are transparent, timely and can lead to health-protective actions

BACKGROUND

In February 2021, over one hundred scientists and policy experts participated in a web-based Workshop to discuss the ways that divergent evaluations of evidence and scientific uncertainties are used to delay timely protection of human health and the environment from exposures to hazardous agents. The Workshop arose from a previous workshop organized by the European Environment Agency (EEA) in 2008 and which also drew on case studies from the EEA reports on 'Late Lessons from Early Warnings' (2001, 2013). These reports documented dozens of hazardous agents including many chemicals, for which risk reduction measures were delayed for decades after scientists and others had issued early and later warnings about the harm likely to be caused by those agents.

RESULTS

Workshop participants used recent case studies including Perfluorooctanoic acid (PFOA), Extremely Low Frequency - Electrical Magnetic Fields (ELF-EMF fields), glyphosate, and Bisphenol A (BPA) to explore myriad reasons for divergent outcomes of evaluations, which has led to delayed and inadequate protection of the public's health. Strategies to overcome these barriers must, therefore, at a minimum include approaches that 1) Make better use of existing data and information, 2) Ensure timeliness, 3) Increase transparency, consistency and minimize bias in evidence evaluations, and 4) Minimize the influence of financial conflicts of interest.

CONCLUSION

The recommendations should enhance the production of "actionable evidence," that is, reliable evaluations of the scientific evidence to support timely actions to protect health and environments from exposures to hazardous agents. The recommendations are applicable to policy and regulatory settings at the local, state, federal and international levels.

Research on the impact mechanism of heterogeneous environmental regulation on enterprise green technology innovation

Green technology innovation (GTI) is an effective way to promote the green development of economy, and government environmental regulations are an important means to encourage enterprises to carry out GTI. Taking Chinese A-share listed enterprises from 2010 to 2019 as samples, this paper divides environmental regulations into three categories: command-based environmental regulation (ER₁), market-based environmental regulation (ER₂) and voluntary environmental regulation (ER₃), studies their impact on enterprise GTI, and discusses the joint effect of enterprise research and development (R&D) investment and government support from the perspective of internal and external linkage of enterprises. In addition, this paper also analyzes the compound effect and time effect of environmental regulation. The research conclusions are as follows: (1) From the perspective of policy types, both ER₁ and ER ₂ could stimulate enterprises to carry out GTI, and the promotion effect of green utility model patents is slightly higher than that of green invention patents. ER₃ inhibits enterprise GTI. In addition, this paper finds that the effect of three environmental regulations acting at the same time is greater than that of one of them. (2) The mechanism analysis shows that the R&D investment of enterprise positively could moderate the relationship between ER₂ and green invention at the significance level of 5%, positively moderate the relationship between ER₂ and green utility model patent at the significance level of 1%, and negatively moderate the relationship between ER₃ and green utility model patent at the significance level of 5%. The government support could moderate the relationship between environmental regulation and green utility model patents at the significance level of 5% and 10%. (3) The effect analysis shows that the transformation rate of GTI in China needs to be improved. The three environmental regulations could have an effect on enterprise GTI in a short period, and ER₁ has the fastest effect. (4) Considering the differences in the level of economic development and resource endowments in various regions of China, this paper classifies the sample enterprises and finds that the impact of environmental regulation on enterprise GTI is heterogeneous in terms of location, ownership nature, factor density and industry type. The research results provide the important reference for the formulation and implementation of environmental regulation policies according to local conditions.

Influence of carbon emission trading policy on residents' health in China

Residents' health is the basic condition for economic and social development. At present, China's environmental pollution problem is becoming increasingly serious, which not only hinders sustainable economic and social development, but also poses a major threat to public health. Therefore, based on the carbon emissions trading policy implemented in China, this paper explores this policy's impact on residents' health using the DID model and illustrates the moderating effect of environmental pollution. The results show that (1) carbon emissions trading policies can promote the improvement of residents' health; (2) the effect is stronger for western regions and provinces with smaller population sizes after taking control variables into consideration; and (3) environmental pollution has a significant moderating effect on the relationship between carbon emissions trading and residents' health. This research serves as an important reference for expanding the scope of the policy pilot, reducing pollutant emissions, and improving the health of the population.

Charting a Path Forward: Assessing the Science of Chemical Risk Evaluations under the Toxic Substances Control Act in the Context of Recent National Academies Recommendations

BACKGROUND

In 2016, Congress enacted the Frank R. Lautenberg Chemical Safety for the 21st Century Act ("the Lautenberg Act"), which made major revisions to the main U.S. chemical safety law, the 1976 Toxic Substances Control Act (TSCA). Among other reforms, the Lautenberg Act mandates that the U.S. Environmental Protection Agency (U.S. EPA) conduct comprehensive risk evaluations of chemicals in commerce. The U.S. EPA recently finalized the first set of such chemical risk evaluations.

OBJECTIVES

We examine the first 10 TSCA risk evaluations in relation to risk science recommendations from the National Academies to determine consistency with these recommendations and to identify opportunities to improve future TSCA risk evaluations by further implementing these key approaches and methods.

DISCUSSION

Our review of the first set of TSCA risk evaluations identified substantial deviations from best practices in risk assessment, including overly narrow problem formulations and scopes; insufficient characterization of uncertainty in the evidence; inadequate consideration of population variability; lack of consideration of background exposures, combined exposures, and cumulative risk; divergent approaches to dose-response assessment for carcinogens and noncarcinogens; and a flawed approach to systematic review. We believe these deviations result in underestimation of population exposures and health risks. We are hopeful that the agency can use these insights and have provided suggestions to produce chemical risk evaluations aligned with the intent and requirements of the Lautenberg Act and the best available science to better protect health and the environment-including the health of those most vulnerable to chemical exposures. https://doi.org/10.1289/EHP9649.

A Unified Probabilistic Framework for Cancer Risk Management

Cancer risk assessments in the regulatory realm are often deterministic. Probabilistic approaches that allow characterizing and propagating uncertainty and variability are better suited to predict the socioeconomic impacts of regulating carcinogens. In this article, I present a unified framework for cancer risk management consisting of (i) a probabilistic exposure model that takes into account variability in individual exposure to the substance of concern; (ii) a probabilistic dose-response model that accounts for differences in individual cancer susceptibility; (iii) an impact assessment model that quantifies individuals' excess lifetime cancer risk; and (iv) a welfare model that values changes in disability-adjusted life expectancy based on workers' willingness-to-pay and aggregates individual valuations across the population at risk. I illustrate the framework with data on occupational exposure to hexavalent chromium in France. In a cohort of 10,000 synthetic workers, about one third of the exposed benefit from the introduction of a binding occupational exposure limit (BOEL). Limiting hexavalent chromium exposure to the BOEL reduces the statistical worker's excess lifetime risk of fatal and nonfatal lung cancer by 4.7E-3 and 1.5E-3, respectively. At cohort level, the risk reduction corresponds to 738.4 full and 30.7 disability-adjusted life years saved. The expected welfare gain of introducing the BOEL is close to €30 million. A major advantage of the framework is its ability to visualize uncertainty and variability inherent to cancer risk assessment. Notwithstanding some implementation challenges, the framework provides a transparent characterization of regulatory impacts that supports informed risk management decisions.

The low but uncertain measured benefits of US water quality policy

US investment to decrease pollution in rivers, lakes, and other surface waters has exceeded $1.9 trillion since 1960, and has also exceeded the cost of most other US environmental initiatives. These investments come both from the 1972 Clean Water Act and the largely voluntary efforts to control pollution from agriculture and urban runoff. This paper reviews the methods and conclusions of about 20 recent evaluations of these policies. Surprisingly, most analyses estimate that these policies' benefits are much smaller than their costs; the benefit-cost ratio from the median study is 0.37. However, existing evidence is limited and undercounts many types of benefits. We conclude that it is unclear whether many of these regulations truly fail a benefit-cost test or whether existing evidence understates their net benefits; we also describe specific questions that when answered would help eliminate this uncertainty.

Framework for determining optimal strategy for sustainable remediation of contaminated sediment: A case study in Northern Taiwan

Contaminated sediment may pose a serious threat to human health and ecosystems. However, sediment remediation is typically an expensive and time-consuming process. Therefore, an effective decision-making process for the remediation of contaminated sediment is essential for identifying the optimal approach. Since a single assessment for sediment remediation may be insufficient, combining different analytical approaches is highly recommended. The objective of this study was to develop a comprehensive assessment framework based on the concept of green and sustainable remediation that considers various environmental, economic, and social aspects for the management of contaminated sediment. We propose a framework based on human health risk assessment (HHRA) and cost-benefit analysis (CBA) and apply the multicriteria decision analysis (MCDA) technique to implement integrated and sustainable strategies for sediment management. We used the framework to determine the best alternative for managing heavy-metal-contaminated sediment in a river in Northern Taiwan. The results of the pre-remediation HHRA indicated an unacceptably high cancer risk to children, while the CBA revealed that a remediation project was economically feasible. Moreover, the results of the MCDA revealed that a strategy involving in-situ capping with anthracite-based activated carbon would be relatively inexpensive and result in low risk to human health. In addition, this strategy would have a higher environmental impact and greater public acceptance as compared to a method involving the dredging and washing of soil. Thus, in this case study, in-situ capping using anthracite-based activated carbon was identified as the preferable remediation alternative from multiple perspectives. The proposed framework should allow decision-makers to choose the optimal integrated management strategy for similar river sites with contaminated sediment.

Preterm birth and economic benefits of reduced maternal exposure to fine particulate matter

Preterm birth (PTB) is a predictor of infant mortality and later-life morbidity. Despite recent declines, PTB rates remain high in the United States. Growing research suggests a possible relationship between a mother's exposure to common air pollutants, including fine particulate matter (PM_2.5), and PTB of her baby. Many policy actions to reduce exposure to common air pollutants require benefit-cost analysis (BCA), and it's possible that PTB will need to be included in BCA in the future. However, an estimate of the willingness to pay (WTP) to avoid PTB risk is not available, and a comprehensive alternative valuation of the health benefits of reducing pollutant-related PTB currently does not exist. This paper demonstrates an approach to assess potential economic benefits of reducing PTB resulting from environmental exposures when an estimate of WTP to avoid PTB risk is unavailable. We utilized a recent meta-analysis, county-level air quality data and county-level PTB prevalence data to estimate the potential health and economic benefits of a reduction in air pollution-related PTB, with PM_2.5 as our case study pollutant. Using this method, a simulated nationwide 10% decrease from 2008 PM_2.5 levels resulted in an estimated reduction of 5016 PTBs and benefits of at least $339 million, potentially reaching over one billion dollars when considering later-life effects of PTB.

Legitimizing Values in Regulatory Science

BACKGROUND

Over the last several decades, scientists and social groups have frequently raised concerns about politicization or political interference in regulatory science. Public actors (environmentalists and industry advocates, politically aligned public figures, scientists and political commentators, in the United States as well as in other countries) across major political-regulatory controversies have expressed concerns about the inappropriate politicization of science. Although we share concerns about the politicization of science, they are frequently framed in terms of an ideal of value-free science, according to which political and economic values have no legitimate role to play in science. For several decades, work in philosophy of science has identified serious conceptual and practical problems with the value-free ideal.

OBJECTIVES

Our objectives are to discuss the literature regarding the conceptual and practical problems with the value-free ideal and offer a constructive alternative to the value-free ideal.

DISCUSSION

We first discuss the prevalence of the value-free ideal in regulatory science, then argue that this ideal is self-undermining and has been exploited to delay protective regulation. To offer a constructive alternative, we analyze the relationship between the goals of regulatory science and the standards of good scientific activity. This analysis raises questions about the relationship between methodological and practical standards for good science, tensions among various important social goods, and tensions among various social interests. We argue that the aims of regulatory science help to legitimize value-laden choices regarding research methods and study designs. Finally, we discuss how public deliberation, adaptive management, and community-based participatory research can be used to improve the legitimacy of scientists as representatives of the general public on issues of environmental knowledge.

CONCLUSIONS

Reflecting on the aims of regulatory science-such as protecting human health and the environment, informing democratic deliberation, and promoting the capacities of environmental justice and Indigenous communities-can clarify when values have legitimate roles in regulatory science. https://doi.org/10.1289/EHP3317.

Demystifying Evidence-Based Policy Analysis by Revealing Hidden Value-Laden Constraints

Consider any choice that affects some social policy. A decision that considers evidence will, at its heart, contain some kind of explicit or implicit "because" statement: "We are doing X because the evidence says Y." But can evidence ever truly speak for itself, in the sense of being reducible to objective utterances that are either correct or in need of correction? Before answering, consider what you'd prefer. Would you rather receive evidence that was free of any value judgments imposed by human actors, that was laden with value judgments that you agree with, or laden with value judgments that you disagree with? The central assertion of this essay is that, throughout policy analysis but especially in assessments of the costs and benefits of regulating versus encouraging new technologies (cost-benefit analysis, or CBA), the first possibility above is a mirage, and the second and third are self-contradictory. Instead, we are overwhelmingly confronted with a fourth possibility: we receive evidence that appears to be (or is deliberately touted as) value neutral but is suffused with hidden value judgments. In the second part of this essay, entitled "A Guided Tour through Inevitable Value Judgments," I identify in a systematic way approximately sixty-five value judgments that are routinely (in some cases, invariably) made in CBA, but that are kept hidden. For each judgment, I discuss its genesis as it is most commonly invoked in CBA, explain how it is hidden in plain sight, and offer one or more value judgments that could be made instead of or in addition to the conventional one. The alternative judgments highlight the width of the spectrum of reasonable conclusions an analyst could reach merely by substituting other judgments for the ones currently embedded. Bringing hidden value judgments to light is doubly valuable. First, it allows discussion to ensue on a level playing field; instead of conclusory statements about what the evidence says, transparency permits statements taking the form of "when channeled through these value judgments, the evidence says this." Perhaps more importantly, transparency about value judgments permits participants in the discussions to offer interpretations of evidence contingent on there being different value judgments chosen at one or more points in the analysis, interpretations that may suggest that alternative course(s) of action are preferable to the one being championed.

Beyond the RfD: Broad Application of a Probabilistic Approach to Improve Chemical Dose-Response Assessments for Noncancer Effects

BACKGROUND

The National Academies recommended risk assessments redefine the traditional noncancer Reference Dose (RfD) as a probabilistically derived risk-specific dose, a framework for which was recently developed by the World Health Organization (WHO).

OBJECTIVES

Our aim was to assess the feasibility and implications of replacing traditional RfDs with probabilistic estimates of the human dose associated with an effect magnitude M and population incidence I (HD_MI).

METHODS

We created a comprehensive, curated database of RfDs derived from animal data and developed a standardized, automated, web-accessible probabilistic dose-response workflow implementing the WHO framework.

RESULTS

We identified 1,464 RfDs and associated endpoints, representing 608 chemicals across many types of effects. Applying our standardized workflow resulted in 1,522 HD_MI values. Traditional RfDs are generally within an order of magnitude of the HD_MI lower confidence bound for I=1% and M values commonly used for benchmark doses. The greatest contributor to uncertainty was lack of benchmark dose estimates, followed by uncertainty in the extent of human variability. Exposure at the traditional RfD frequently implies an upper 95% confidence bound of several percent of the population affected. Whether such incidences are considered acceptable is likely to vary by chemical and risk context, especially given the wide range of severity of the associated effects, from clinical chemistry to mortality.

CONCLUSIONS

Overall, replacing RfDs with HD_MI estimates can provide a more consistent, scientifically rigorous, and transparent basis for risk management decisions, as well as support additional decision contexts such as economic benefit-cost analysis, risk-risk tradeoffs, life-cycle impact analysis, and emergency response. https://doi.org/10.1289/EHP3368.

Targeting cleanups towards a more sustainable future

A tension arises between society's disposition to protect people at risk from environmental pollution, and an aversion towards the potential harmful side-effects associated with cleanup activities. Here we explore how setting different cleanup standards may influence some of the environmental, social, and economic side-effects of remediation, and how they can be quantified for incorporation into cleanup target setting; these include (1) secondary environmental impacts, assessed by life cycle assessment (LCA); (2) fatalities and injuries, assessed by actuarial risk analysis; and (3) the cost effectiveness of stringent cleanup standards, assessed by the incremental cost-effectiveness ratio (ICER). We argue that only by using optimal cleanup standards that integrate quantified remediation side-effects with health risk assessment (HRA) can the green and sustainable remediation (GSR) movement maximize its potential. Together, the combined approaches may provide a more holistic management of risks for a more sustainable future.