According to many individuals, pollutants and pathogens are different causes of diseases. However, modern research shows that these can interact to alter the response of animals and people to contagious diseases.
Environmental pollutants seem to weaken the immune system, increase pathogen virulence, and reduce vaccine efficacy, as stated in an article in Chemical & Engineering News (C&EN), the weekly newsmagazine of the American Chemical Society.
In the past two decades, scientists have shown that mice were more prone to influenza virus when exposed to low levels of a dioxin known as 2,3,7,8-tetrachlorodibenzo-p-dioxin. Since then, many studies have proposed that other chemicals, like mercury, perfluorooctanoic acid, and arsenic, also have the potential to change immune responses and reduce the resistance of animals to infectious diseases.
In addition, epidemiological studies in humans have associated exposure of chemical in the womb with a child’s increased risk of epidemic disease. Senior Editor Britt E. Erickson has written that only currently, however, researchers have started to reveal how this occurs.
Compounds such as per- and polyfluoroalkyl substances (PFAS) are extensively used in everyday goods, such as nonstick products, food packaging, and cleaners. Scientists have associated the increased concentrations of some PFAS in the blood of mothers with decreased responses to vaccinations and more illnesses in their children.
Likewise, exposure to arsenic in the womb has been associated with reduced levels of antibodies against diphtheria in immunized Bangladeshi children. Experimental evidence also suggests that a few chemicals, like lead or zinc, can possibly contribute to the increase of multidrug-resistant strains of methicillin-resistant Staphylococcus aureus (MRSA). Erickson has written that such interactions are complicated and will need further interdisciplinary research in infectious disease and environmental health.