Whither Risk Assessment: New Challenges and Opportunities a Third of a Century After the Red Book

Practical Opportunities to Improve the Impact of Health Risk Assessment on Environmental and Public Health Decisions

Following alerts about the diminishing role of health risk assessment (HRA) in informing public health decisions, this study examines specific HRA topics with the aim of identifying possible solutions for addressing this compelling situation. The study administered a survey among different groups of stakeholders involved in HRA or decision-making, or both. The responses show various understandings of HRA in the decision-making context-including confusion with the health impact assessment (HIA)-and confirm recurring foundational issues within the risk analysis field that contribute to the growth of inconsistency in the HRA praxis. This inconsistency lowers the effectiveness of HRA to perform its primary purpose of informing public health decisions. Opportunities for improving this situation come at the beginning of the assessment process, where greater attention should be given to defining the assessment and decision-making contexts. Both must reflect the concerns and expectations of the stakeholders regarding the needs and purpose of an HRA on one side, and the methodological and procedural topics relevant for the decision case at hand on the other. The HRA process should end with a decision follow-up step with targeted auditing and the participation of stakeholders to measure its success.

Human Biomonitoring Data in Health Risk Assessments Published in Peer-Reviewed Journals between 2016 and 2021: Confronting Reality after a Preliminary Review

Human biomonitoring (HBM) is a rapidly developing field that is emphasized as an important approach for the assessment of health risks. However, its value for health risk assessment (HRA) remains to be clarified. We performed a review of publications concerned with applications of HBM in the assessment of health risks. The selection of publications for this review was limited by the search engines used (only PubMed and Scopus) and a timeframe of the last five years. The review focused on the clarity of 10 HRA elements, which influence the quality of HRA. We show that the usage of HBM data in HRA is limited and unclear. Primarily, the key HRA elements are not consistently applied or followed when using HBM in such assessments, and secondly, there are inconsistencies regarding the understanding of fundamental risk analysis principles and good practices in risk analysis. Our recommendations are as follows: (i) potential usage of HBM data in HRA should not be non-critically overestimated but rather limited and aligned to a specific value for exposure assessment or for the interpretation of health damage; (ii) improvements to HRA approaches, using HBM information or not, are needed and should strictly follow theoretical foundations of risk analysis.

Study on the Spatial Classification of Construction Land Types in Chinese Cities: A Case Study in Zhejiang Province

Identifying the land-use type and spatial distribution of urban construction land is the basis of studying the degree of exposure and the economic value of disaster-affected bodies, which are of great significance for disaster risk predictions, emergency disaster reductions, and asset allocations. Based on point of interest (POI) data, this study adopts POI spatialization and the density-based spatial clustering of applications with noise (DBSCAN) algorithm to accomplish the spatial classification of construction land. Zhejiang province is selected as a study area, and its construction land is divided into 11 land types using an accurate spatial classification method based on measuring the area of ground items. In the research, the POI dataset, which includes information, such as spatial locations and usage types, was constructed by big data cleaning and visual interpretation and approximately 620,000 pieces in total. The overall accuracy of the confusion matrix is 76.86%, which is greatly improved compared with that constructed with EULUC data (61.2%). In addition, compared with the official statistical data of 11 cities in Zhejiang Province, the differences between the calculated spatial proportions and statistics are not substantial. Meanwhile, the spatial characteristics of the studied land-use types are consistent with the urban planning data but with higher accuracy. The research shows that the construction land in Zhejiang Province has a high degree of land intensity, concentrated assets, and high economic exposure. The approach proposed in this study can provide a reference for city management including urbanization process, risk assessment, emergency management and asset allocation.

Improving Health Risk Assessment as a Basis for Public Health Decisions in the 21st Century

One-fifth of the way through the 21st century, a commonality of factors with those of the last 50 years may offer the opportunity to address unfinished business and current challenges. The recommendations include: (1) Resisting the tendency to oversimplify scientific assessments by reliance on single disciplines in lieu of clear weight-of-evidence expressions, and on single quantitative point estimates of health protective values for policy decisions; (2) Improving the separation of science and judgment in risk assessment through the use of clear expressions of the range of judgments that bracket protective quantitative levels for public health protection; (3) Use of comparative risk to achieve the greatest gains in health and the environment; and (4) Where applicable, reversal of the risk assessment and risk management steps to facilitate timely and substantive improvements in public health and the environment. Lessons learned and improvements in the risk assessment process are applied to the unprecedented challenges of the 21st century such as, pandemics and climate change. The beneficial application of the risk assessment and risk management paradigm to ensure timely research with consistency and transparency of assessments is presented. Institutions with mandated stability and leadership roles at the national and international levels are essential to ensure timely interdisciplinary scientific assessment at the interface with public policy as a basis for organized policy decisions, to meet time sensitive goals, and to inform the public.

Setting Air Quality Standards for PM2.5 : A Role for Subjective Uncertainty in NAAQS Quantitative Risk Assessments?

The U.S. Clean Air Act (CAA) requires the Administrator of the U.S. Environmental Protection Agency (EPA) to set and periodically review national ambient air quality standards (NAAQS) for criteria pollutants. Because NAAQS must be set without balancing health risks against cost, Administrators look for where health risk tapers off. For some pollutants, however, no evidence exists of such a diminishment. The Administrator must instead evaluate how the strength of evidence for the scientific validity of risk estimates weakens for exposure levels below the central mass of observations indicating a pollutant-health risk relationship. Such an evaluation requires judgments about uncertainties that are inherently subjective. The risk assessments the Agency prepares during NAAQS reviews provide a natural platform for quantitatively characterizing these subjective uncertainty judgments, but the Agency is no longer making use of this opportunity. This article describes EPA's early development of methods to quantitatively characterize subjective uncertainty in NAAQS risk assessments, then traces the progressive elimination of such uncertainty analysis in the risk assessments for the three past NAAQS reviews for fine particulate matter (PM_2.5 ), even while judgments about this uncertainty were becoming increasingly central to Administrators' NAAQS decisions. As a result, the risk assessments now lack relevance to NAAQS decision making. To reestablish a meaningful decision-support role for NAAQS risk assessments, this article suggests alterations to the process of preparing them. Taking no position on the scientific or legal appropriateness of past NAAQS decisions, the suggested process is intended to better synthesize the scientific evidence to better inform (without constraining) the Administrator's policy decisions.

An Emerging New Risk Analysis Science: Foundations and Implications

To solve real-life problems-such as those related to technology, health, security, or climate change-and make suitable decisions, risk is nearly always a main issue. Different types of sciences are often supporting the work, for example, statistics, natural sciences, and social sciences. Risk analysis approaches and methods are also commonly used, but risk analysis is not broadly accepted as a science in itself. A key problem is the lack of explanatory power and large uncertainties when assessing risk. This article presents an emerging new risk analysis science based on novel ideas and theories on risk analysis developed in recent years by the risk analysis community. It builds on a fundamental change in thinking, from the search for accurate predictions and risk estimates, to knowledge generation related to concepts, theories, frameworks, approaches, principles, methods, and models to understand, assess, characterize, communicate, and (in a broad sense) manage risk. Examples are used to illustrate the importance of this distinct/separate risk analysis science for solving risk problems, supporting science in general and other disciplines in particular.

Assessment of Health Risk from Historical Use of Cosmetic Talcum Powder

This study's objective is to assess the risk of asbestos-related disease being contracted by past users of cosmetic talcum powder.  To our knowledge, no risk assessment studies using exposure data from historical exposures or chamber simulations have been published. We conducted activity-based sampling with cosmetic talcum powder samples from five opened and previously used containers that are believed to have been first manufactured and sold in the 1960s and 1970s.  These samples had been subject to conflicting claims of asbestos content; samples with the highest claimed asbestos content were tested.  The tests were conducted in simulated-bathroom controlled chambers with volunteers who were talc users.  Air sampling filters were prepared by direct preparation techniques and analyzed by phase contrast microscopy (PCM), transmission electron microscopy (TEM) with energy-dispersive x-ray (EDX) spectra, and selective area diffraction (SAED).  TEM analysis for asbestos resulted in no confirmed asbestos fibers and only a single fiber classified as "ambiguous."  Hypothetical treatment of this fiber as if it were asbestos yields a risk of 9.6 × 10^-7 (under one in one million) for a lifetime user of this cosmetic talcum powder.  The exposure levels associated with these results range from zero to levels far below those identified in the epidemiology literature as posing a risk for asbestos-related disease, and substantially below published historical environmental background levels.  The approaches used for this study have potential application to exposure evaluations of other talc or asbestos-containing materials and consumer products.