Pesticides as a cause of occupational skin diseases in farmers.

Pesticides are chemical substances used in agricultural production to protect crops against pests. They help to achieve better quality and quantity of crops; however, they also are capable of causing occupational diseases in farmers. Skin is the most exposed organ while spraying the pesticide on fields. Farmers are also exposed to pesticides while mixing, loading the pesticide as well as while cleaning the equipment and disposing of empty containers. Other activities associated with exposure are sowing pesticide-preserved seeds, weeding and harvesting previously sprayed crops. During the first decades of using pesticides the main problem was the risk of acute intoxication among people occupationally exposed. With decrease in the toxicity of improved pesticides, attention was turned to chronic intoxication and environmental contamination. Nowadays, the problem of diseases not immediately related to the toxic potential of pesticides gains increasing interest. The majority of these non-toxic diseases are dermatoses. Most pesticide-related dermatoses are contact dermatitis, both allergic or irritant. Rare clinical forms also occur, including urticaria, erythema multiforme, ashy dermatosis, parakeratosis variegata, porphyria cutanea tarda, chloracne, skin hypopigmentation, nail and hair disorders. Farmers exposed to arsenic pesticides are at risk of occupational skin cancer, mostly morbus Bowen (carcinoma in situ), multiple basal cell carcinomas and squamous cell carcinomas. Non-arsenic pesticides, e.g. paraquat, are also potentially carcinogenic.