A recent study from Sweden shows that background exposure — or long-term, low dose exposure — to persistent organic pollutants (POPs) may play an important role in the development or progression of stroke in the elderly.
Research has shown that exposure to POPs can lead to such chronic health problems as diabetes, obesity and hardening of the arteries leading to cardiovascular trouble. The recent Swedish study adds to this litany of human health harms.
Due to the harm they cause to human health and the environment, POPs have been on PAN's radar for a long time now. Way back in the early 1980's, our international Dirty Dozen campaign focused global attention on POPs pesticides, which helped lead to the formation of the Stockholm Convention, a global treaty that targets the most egregious POPs chemicals for phaseout around the world. PAN continues to remain actively engaged in campaigns on POPs pesticides in the U.S. and overseas.
With a sample size of almost 900 people aged 70 years, researchers from Uppsala University in Sweden found that background exposure to POPs such as PCBs and DDE (a breakdown product of DDT) may play an important role in development or progression of stroke. The researchers measured the concentration of POPs in the study subjects’ plasma and then tracked the development of strokes in the study population.
Some of the key risk factors for stroke include high blood pressure, diabetes, hardening of arteries (atherosclerosis), high levels of cholesterol or fats in the blood (dyslipidemia) and obesity. Studies have previously shown that exposure to POPs can lead to the development or worsening of each of these conditions. The study authors stated that:
Taken together with previous experimental and epidemiological studies, POPs may play a fundamental role in the development of stroke.
Stroke is the fourth leading cause of death in the U.S. and a leading cause of adult disability. Exposure to POPs being linked to an increased risk of stroke is therefore profoundly disturbing news.
Though the majority of POPs pesticides have already been banned in the U.S., the chemicals can last for decades in the environment and in human bodies. These persistent chemicals also travel on wind and water currents across national boundaries — the impetus for a global treaty, since protective action at a national level cannot address the problem.
People in the U.S. continue to be exposed to POPs through a variety of sources including food, residues in the soil and water, and direct contact with POPs. A number of populations are at particular risk of POPs exposure, including people whose diets include large amounts of fish, shellfish or wild foods that are high in fat. Since POPs chemicals tend to settle in the Arctic region after traveling the globe, Arctic communities face higher levels of exposure.
The Swedish study should sound an alarm bell for all of us, since the increased risk of stroke was not linked to occupational or high dose exposures. Though people can take precautions at the individual level by reducing or eliminating the consumption of fatty foods and dairy, the problem will only be solved through speeding the elimination of POPs worldwide through rapid and effective implementation of the Stockholm Convention.