Microplastics (MP) in Drinking Water Linked with Colorectal Cancer Across Urban-Rural Counties of Maryland

Author(s): Millen Singh, MD

Microplastics, defined as plastic particles less than 5 mm in diameter, are evident in the environment and a growing public health concern because they are found in drinking water systems. Here, we investigate the correlation between microplastic levels in drinking water and colorectal cancer rates in Maryland. Drinking water samples were collected and analyzed. Statistical analyses were conducted to test the relationship between microplastic concentration in drinking water and colorectal cancer incidence. Some rural Maryland counties tended to show significantly higher microplastic concentrations in the drinking water than their urbanized counterparts. Even though one would expect urbanized areas with higher population density and plastic waste generation to show higher microplastic concentrations in their drinking water. Adding to this unexpected pattern, the same rural counties (Allegany, Caroline and Dorchester) that had the highest microplastic contamination in their drinking water were also noted to have the highest incidence of colorectal cancer rates in the state of Maryland. This research highlights the importance of addressing microplastic contamination in drinking water, the pathways through which it enters public systems and its broader implications for public health policies and practices. By identifying potential risks, this study contributes to a growing body of knowledge on environmental toxins and their impact on human health, and to our knowledge, it is the first study that shows a correlation between microplastic-contaminated drinking water in rural counties of Maryland and increased colorectal cancer rates.