Many chemicals have the potential to contaminate drinking water. Pesticides, for instance, are applied to farmlands, gardens and lawns and can make their way into ground water or surface water systems that feed drinking water supplies.

Whether these contaminants pose a health risk depends on how toxic the contaminants are, how much is in the water, and how much exposure occurs on a daily basis.

However, most contaminants found in drinking water influence brain development, particularly in children and older adults. In the elderly, vision, hearing and balance might be altered through chronic exposure to a range of chemicals including heavy metals, phthalates, arsenic, pesticides, phenols, hydrocarbons and polyfluorinated compounds. And it has been further observed that these chemicals might lead to difficulties in thinking or remembering as well. It is thought that these chemicals may disrupt nerve regulation in the brain.

  • Pesticides as well as heavy metals, are potentially toxic to humans and can have both acute and chronic health effects, depending on the quantity and the ways in which a person is exposed.
  • Some of the older, cheaper pesticides can remain in the soil and water for years. They have been banned in developed countries for agricultural use but are still used in many developing countries.
  • There are more than 1,000 pesticides used around the world to ensure food is not damaged or destroyed by pests. Each pesticide has different properties and toxicological effects (and the toxicological effects of multiple pesticides can be greater than the sum of their parts).
  • Environmental chemicals may be associated with oral health problems as well. In a recent study, it was found that people with gum disease, bone loss around the mouth, and teeth loose not due to injury were found to have higher levels of heavy metals, phthalates, phenols, parabens and pesticides (among other chemicals) in their urine. Such harmful exposure could cause defects in the development of tooth enamel.

The health effects of pesticides, chemicals and other pollutants depend on the chemical structure. Some, such as the organophosphates and carbamates, affect the nervous system. Others may irritate the skin or eyes. Some pesticides may be carcinogens (cancer causing). Others may affect the hormone or endocrine system in the body. Pesticide mixtures may be derived from common sources (such as point sources) or from multiple nonpoint sources, and may include several different types of pesticide compounds with different mechanisms of toxicity.