Divine Aleru is an accomplished biochemist and researcher with a specialized background in environmental toxicology, focusing on the impacts of heavy metals on human health. With deep-rooted expertise in microbiome signatures analysis, Divine seamlessly blends rigorous scientific training with her passion for deciphering the intricate relationships between environmental exposures and the human microbiome. Her career is distinguished by a commitment to advancing integrative health interventions, leveraging cutting-edge microbiome research to illuminate how toxic metals shape biological systems. Driven by curiosity and innovation, Divine is dedicated to translating complex environmental findings into actionable insights that improve individual and public health outcomes. 
Divine Aleru is an accomplished biochemist and researcher with a specialized background in environmental toxicology, focusing on the impacts of heavy metals on human health. With deep-rooted expertise in microbiome signatures analysis, Divine seamlessly blends rigorous scientific training with her passion for deciphering the intricate relationships between environmental exposures and the human microbiome. Her career is distinguished by a commitment to advancing integrative health interventions, leveraging cutting-edge microbiome research to illuminate how toxic metals shape biological systems. Driven by curiosity and innovation, Divine is dedicated to translating complex environmental findings into actionable insights that improve individual and public health outcomes. What was issued?
The analysis reviewed the impact of the Environmental Protection Agency’s (EPA) maximum contaminant level (MCL) for arsenic in drinking water on exposure levels in the United States, from 2003 to 2014. This MCL, set at 10 µg/L, was implemented in 2006, aiming to reduce arsenic exposure from public water systems. The study, using data from the National Health and Nutrition Examination Survey (NHANES), tracked trends in urinary arsenic levels, which reflect drinking water contamination. The study specifically assessed the reductions in arsenic exposure among people using public water systems and private wells. It found that public water users experienced a decline in exposure over the years, but private well users, who are not subject to the MCL, showed no such change.
Who is affected?
The findings are relevant to several stakeholders. The general public, especially those relying on public water systems, benefits from the regulations, as it leads to reduced arsenic exposure, lowering associated cancer risks. However, private well users, who are not covered by the MCL, remain vulnerable to arsenic contamination. The study also impacts regulatory bodies like the EPA, which must consider the effectiveness of their rules and enforcement practices. Public health officials, environmental groups, and food industry stakeholders must also be aware of the disparities in exposure risks between different water sources.
Most important findings
The study found that urinary arsenic levels, which serve as biomarkers for arsenic exposure, significantly declined among public water users, from 3.01 µg/L in 2003–2004 to 2.49 µg/L in 2013–2014, indicating a 17% reduction. No such decline was observed in private well users, where arsenic exposure remained steady. The analysis projected that the reduction in exposure due to the MCL has likely prevented 200 to 900 lung and bladder cancer cases per year. This reduction was particularly noticeable among Mexican-American populations, where exposure decreased by 36% for DMA (dimethylarsinate), a key arsenic metabolite. These reductions suggest that the MCL’s enforcement and infrastructure improvements in public water systems have had a positive effect on reducing arsenic exposure.
Key implications
For industry stakeholders, this research underscores the importance of complying with federal drinking water standards, as failure to meet these guidelines can leave communities at risk of long-term health consequences. The findings suggest that future regulatory actions should focus on private wells, which remain a significant source of arsenic exposure. For public health, this study highlights the effectiveness of water regulation in reducing cancer risks. However, it also points out the gaps in protection for households relying on private wells, urging greater efforts for arsenic testing and treatment in these regions. The results reinforce the need for continuous monitoring and enforcement to protect vulnerable populations.
Citation
Nigra, A. E., Sanchez, T. R., Nachman, K. E., Harvey, D., Chillrud, S. N., Graziano, J. H., & Navas-Acien, A. (2017). The effect of the Environmental Protection Agency maximum contaminant level on arsenic exposure in the USA from 2003 to 2014: An analysis of the National Health and Nutrition Examination Survey (NHANES). Lancet Public Health, 2(11), e513–e521. https://doi.org/10.1016/S2468-2667(17)30195-0
Arsenic is a naturally occurring metalloid that ranks first on the ATSDR toxic substances list. Inorganic arsenic contaminates water, rice and consumer products, and exposure is linked to cardiovascular disease, cognitive deficits, low birth weight and cancer. HMTC’s stringent certification applies ALARA principles to protect vulnerable populations.
