A post-remediation assessment in Jersey City of the association of hexavalent chromium in house dust and urinary chromium in children

Information needs, approaches, and case studies in human health risk communication

This article uses ten case studies to illustrate the information needs, various communication approaches, and the communicator's role in explaining environmental health risks from a variety of hazards, to a variety of audiences, over time frames from days to years, using in person consultation, lectures, zooms, and email formats. Events often had a long history before the communication began and may have had a long tail afterward. Audiences may be public officials, companies, workers, communities, or individuals. Each individual may have their own understanding or mental model regarding the hazard, exposure, and risk. The communicator's role or intention may be to reassure an audience that has unrealistic exaggerated concerns or fears or to protect a client if the fears are realistic. Or it may be altruistic to inform a complacent audience to take the risks it faces more seriously. Although risk assessment research has advanced the techniques for communicating abstruse probabilities to audiences with low numeracy, in my experience, audiences are unimpressed by precise-sounding probability numbers, and are more interested in whether exposure is occurring or may occur and how to stop it. Often audiences have reason to be outraged and may be more concerned about punishing wrong doers than about the hazard itself, particularly when the exposure is past and cannot be undone. Thus, there is a difference between discussing the riskiness of a situation (risk communication) and what you are going to do about the situation (risk management). Risk communication is successful when the audience responds as intended, calming down or taking action. These case studies are drawn from a large number of risk communication experiences that I and my Rutgers colleagues have engaged in over the past four decades. Through the 20th century, New Jersey was the most densely industrialized State in United States. New Jersey experienced growth of the chemical and petrochemical industries and the unfortunately profligate disposal of toxic wastes. Having the most Superfund sites of any state is a dubious distinction, but New Jersey also has the most experience in evaluating and responding to these hazards.

Multiple exposure pathways and urinary chromium in residents exposed to chromium

BACKGROUND

Environmental hexavalent chromium contamination in northeast China has been ongoing for over 60 years and health outcomes related with chromium (Cr) pollution were observed in polluted arears, but exposure pathways remains unclear. This study aims to evaluate the association between Cr exposure dose through multiple exposure pathways and Cr concentration in urine, and identify the most contributed pathway.

METHODS

We used risk assessment tools with individual exposure parameters to estimate eight individual Cr exposure doses (CD) for three exposure routes (inhalation, ingestion, and dermal contact) with four environmental media (underground water, soil, household dust, and PM₁₀ in ambient air) in 134 residents living in three chromium polluted villages. We used the covariate-adjusted standardized urinary Cr concentration (casUCr) as the internal Cr exposure biomarker. Ridge Regression, Weighted Quantile Sum Regression (WQS) and Bayesian Kernel Machine Regression (BKMR) models were used to assess the effect of overall eight CDs on urine Cr concentration and compare the contribution of each CD.

RESULTS

In the ridge regression analysis, Cr exposure through ingestion of dust (βstd = 0.418, p-value = 0.009), inhalation of dust (βstd = 0.384, p = 0.031) and dermal contact with soil (βstd = 0.264, p = 0.192) had the highest impact on casUCr. In the WQS model, the overall CDs demonstrated a non-significant positive association with casUCr. CDs of dust ingestion, air inhalation and dust inhalation had the largest contribution on casUCr when fitted in the WQS model. In the BKMR model, the hierarchical variable selection showed that casUCr was mainly affected by CDs of household dust and dermal contact with soil. CD of dermal contact with soil exhibited a negative association with casUCr, while CDs of dust showed positive or non-linear trend.

CONCLUSIONS

This research proposed a new method to calculate individual Cr exposure dose of multi-pathway and applied different statistical methods to identify predominant pathway. For this study, Cr exposure through dust has the strongest effect on Cr concentration in urine. The results could help conduct target interventions to reduce Cr intake, such as blocking dust exposure to reduce Cr uptake for villagers living in these contaminated areas.

Mass Spectrometry for Investigating the Effects of Toxic Metals on Nucleic Acid Modifications

The extensive use of toxic metals in industry and agriculture leads to their wide distribution in the environment, which raises critical concerns over their toxic effects on human health. Many toxic metals are reported to be mildly mutagenic or non-mutagenic, indicating that genetic-based mechanisms may not be primarily responsible for toxic metal-induced carcinogenesis. Increasing evidence has demonstrated that exposure to toxic metals can alter epigenetic modifications, which may lead to the dysregulation of gene expression and disease susceptibility. It is now becoming clear that a full understanding of the effects of toxic metals on cellular toxicity and carcinogenesis will need to consider both genetic- and epigenetic-based mechanisms. Uncovering the effects of toxic metals on epigenetic modifications in nucleic acids relies on the detection and quantification of these modifications. Mass spectrometry (MS)-based methods for deciphering epigenetic modifications have substantially advanced over the past decade, and they are now becoming widely used and essential tools for evaluating the effects of toxic metals on nucleic acid modifications. This Review provides an overview of MS-based methods for analysis of nucleic acid modifications. In addition, we also review recent advances in understanding the effects of exposure to toxic metals on nucleic acid modifications.