Health, Safety and Environment - International Labour Organization

Manual 5:PESTICIDES AND HEALTH,SAFETY & THE ENVIRONMENTEXAMPLES OF HEALTH EFFECTS OF SPECIFIC PESTICIDESHerbicidesParaquatParaquat is a total, contact herbicide used for the control of both broadleaved plants andgrasses, and is one of the most widely used pesticides globally. This pesticide activeingredient is acutely toxic and with no effective antidote in case of poisoning.Highlights Life-threatening effects on the gastro-intestinal (GI) tract, kidney, liver, heart and otherorgans. The LD 50 in humans is approximately 3-5 mg/kg, which translates into as littleas 10-15 milliltres (mL) of a 20% solution The usual cause of death is pulmonary fibrosis which is a thickening and stiffening of thelining of the air sacs (alveoli) of the lungs, causing progressive breathlessness.Signs and symptoms Ingestion: burning pain in the mouth, throat, chest, upper abdomen; pulmonary oedema(excessive accumulation of body fluid in the lungs); pancreatitis (inflammation of thepancreas); other renal, and central nervous system (CNS) effects Dermal: dry and fissured hands, horizontal ridging or loss of fingernails, skin ulcerationand abrasion. Dermal signs are common among agricultural workers with acute paraquattoxicity. Fatal poisonings are reported to have occurred as a result of protracted dermalcontamination by paraquat, but this is likely to occur only when the skin is abraded,eroded or diseased Inhalation: toxicity from breathing in paraquat is rare, though some agricultural workerscan be exposed through prolonged inhalation of spray droplets, and develop nosebleedsdue to local damage.GlyphosateThe pesticide active ingredient, glyphosate,is one of the most widely used herbicidesglobally. Its use is expanding with the introduction of genetically modified, Roundup Ready(Roundup is a commercial name for glyphosate) seeds.Because of its low acute toxicity rating, glyphosate competes effectively with paraquatwhich is more acutely toxic. However, the toxicity of the pesticide product depends on itsformulation and several glyphosate formulations are more toxic than the glyphosate itself.There is substantial evidence of human poisonings from the use of this pesticide.Since glyphosate is absorbed by plants it cannot be completely removed by washing or peelingproduce nor by milling, baking or brewing. It can persist in food products for up to two years.Its use as a pre-harvest desiccant and growth regulator is particularly problematic with respectto residues as there is insufficient time after use for the chemical to degrade before harvest.Acute toxicityGlyphosate is listed in the WHO classification in Class IV (Table 5) – Unlikely to present anacute hazard in normal use, and by the US Environmental Protection Agency in ToxicityClass III – Mild irritant. However, several of its formulations are often more toxic dependingon the ingredients in the formulation.227 Health, Safety and EnvironmentA Series of Trade Union EducationManuals for Agricultural Workers