Choosing the chemicals to be investigated
At the start of the DEMOCOPHES project, Bisphenol-A was added as an additional optional biomarker. This was seen as a test of the feasibility of adding ‘new’ biomarkers quickly to the EU-harmonised HBM programme, i.e. with some uncertainties at the scientific level.
To facilitate recruitment and sampling, blood samples were not taken during this project.
Mercury is a naturally occurring element in the earth’s crust. It is also released into the environment through man-made sources such as the burning of fossil fuels, waste incineration, forest fires and waste-water discharge from plastic production plants. The mercury released into the air and water is washed into seas and oceans, ending up in fish. Large fish at the top of the food chain are particularly affected by this pollution. Chronic exposure to mercury can cause damage to the central nervous system, kidneys and stomach. It also affects the immune system, blood pressure and may cause behavioural problems. During pregnancy, methylmercury compounds cross the placenta and can affect the development of the foetus, causing neurodevelopmental abnormalities and loss of Intelligence Quotient (IQ).
Cadmium is a metal present in small quantities in air, water and soil. It is a by-product of the extraction of zinc, lead and copper and is used in batteries and paint. Exposure to cadmium is primarily through active and passive smoking but it is also present in some food types such as vegetables, shellfish and liver. High levels of cadmium can cause cancer in humans. Long-term exposure to low levels of cadmium through air, water and soil can affect the kidneys, bone density and the cardiovascular system.
Cotinine is formed from nicotine after it enters the human body. It is an excellent biomarker of exposure to tobacco smoke and is detectable for several days after inhalation. Smoking may cause lung cancer, heart disease and respiratory diseases. Non-smoking adults and children exposed to second-hand smoke face the same dangers as smokers themselves. Children exposed to tobacco smoke have an increased risk of sudden infant death, chest infections and asthma. Exposure to tobacco smoke during pregnancy can result in low birth weights in newborns and pre-term deliveries.
Phthalates are a group of compounds widely used in the manufacture of plastics, to make them soft and flexible, and in personal care products. They are widespread, found in common products such as soaps, suntan lotion, soft plastic toys, plastic bottles, raincoats, shoes and food packaging. Continuous and repeated exposure to high levels is associated with changes in the hormonal system, causing a decrease in fertility, premature births and genital defects, among other consequences. More research is needed to assess the exact health effects of long-term exposure to low levels of phthalates.
Bisphenol-A (BPA) is used in coatings on the inside of cans, in plastics, in paints, varnishes and glues, and in the thermal paper used, for example, in supermarkets’ cash tickets. In animal experiments, elevated levels of BPA are linked to fertility and developmental problems, cardiovascular disorders and diabetes, among other conditions. More research is needed to assess the exact health effects of long-term exposure to low levels of BPA.