Environmental science: Assessing the impact of hazardous waste sites on human health

Living in close proximity to a superfund site (an area contaminated with hazardous substances) in the United States may decrease average life expectancy by 0.2 years, according to a new study in Nature Communications. These impacts could be further exacerbated by sociodemographic disadvantage and the impacts of climate change, the research suggests.

Millions of people across the United States live near superfund sites, each of which is characterized by the presence of hazardous wastes that require long-term clean-up efforts. The potential health impacts associated with proximity to superfund sites have not been assessed on a national level.

Hanadi Rifai and colleagues use a nationwide, geocoded statistical modelling analysis with census data to estimate how life expectancy, as a proxy for general health, is influenced by nearness to superfund sites. Life expectancy data were available for more than 65,000 of the 72,268 census tracts within the contiguous US. They find a small but significant difference between the life expectancies of people living close to superfund sites (within their census tracts) versus those who live further away from sites (none within their census tracts). The average decrease in life expectancy was found to be around 0.2 years, but there was a reduction of about 1.22 years for those in census tracts with both close proximity to superfund sites and sociodemographic disadvantages, such as low income, low education level, lack of citizenship, lack of insurance, or disabilities, relative to those with disadvantages not sharing census tracts with superfund sites.

A region’s preparedness and response to natural hazards like floods, which can disperse toxic chemicals and contaminate water supplies, also compounded the adverse effects of living near a superfund site. These impacts could become more pronounced in the future as climate change increases the frequency of such events. Health impacts were also higher in census tracts where hazardous waste clean-up plans were not put in place. However, the authors note that each superfund site requires individual investigation to more accurately estimate the harmful effect of its presence, if any, on people living in the vicinity of the site.

After the embargo ends, the full paper will be available at: https://www.nature.com/articles/s41467-021-22249-2