Nanotechnology and environment: Safety and health in exposure to nanoparticles and ceramics.

The first pesticide synthesized was the dichloro diphenyl trichloroethane in 1874. In 1998, 20,000 commercial products were registered as pesticides by the US Environmental Agency of Protection. The classification, according to their toxicity, pesticides can be classified as extremely dangerous, highly dangerous, moderately dangerous and slightly dangerous. According to their median lifetime, they are classified as permanent, persistent, moderately persistent and not persistent. Given their chemical structure, they are classified in several groups, the most utilized of which are organochlorines, organophosphates, carbamates and pyrethrins. Agriculture, public health, structural pest control, industry, green area servicing and the maintenance of reservoirs of water are the main activities in which pesticides are currently employed. The main sources of pesticide exposure to humans are through the food chain, air, water, soil, flora and fauna. While acute poisoning generally affects farmers and industrial workers, chronic poisoning is more common in the general population. Pesticides are mainly absorbed through dermal, respiratory and oral pathways. Although absorption through the skin is prominent in the work environment, the general population are more at risk from ingestion and inhalation. Pesticides are distributed all around the human body through the bloodstream and are eliminated through urine, faces and exhaled air. The main techniques employed in the assessment of pesticides exposure are the history of exposure, the experts evaluation and environmental and biological monitoring.