|Initial Environmental Assessment: Plant Protection - Series no 13 (NORAD, 1995)|
|Part I: General account|
|3 Possible environ mental impacts|
The health risks of pesticide use include acute poisoning as
well as injuries evolving over time. The spraying personnel can be poisoned by
getting pesticide on the skin or in the respiratory passages. Chronic poisoning
can be the result of long-term exposure to pesticides. The injury can appear a
long time after the exposure to the pesticide. Carcinogenic pesticides are an
example of chronic poisoning. Today, all new pesticides are examined for any
carcinogenic effects, potential foetal injury or mutagenic effects. Pesticides
causing such injuries will not be given official approval.
The following aspects influence the prospective health risk of a pesticide:
· The degree of toxicity when in direct contact with the skin, the digestive organs or the respiratory passages.
· The handling of the pesticide. Whether the pesticide is handled in such a way that it can enter the body.
· The chemical properties of the pesticide, such as solubility in water, fat solubility and acidity, which can be of decisive importance with regard to uptake in or direct contact with the body.
· The immune defence and health condition of the body.
· The use of alcohol, tobacco or other toxicants which can increase the risk of poisoning.
Distribution and storage: Pesticides must be regarded as hazardous toxicants during transport, storage and distribution (see chapter 1.5). Spillage of liquids from cans and spraying powder from broken bags can expose a lot of people to health risks. If the pesticide is stored in rooms with bad ventilation or is placed on shelves in shops, cooperatives or other outlets, pesticide spillage can expose both staff and customers to health risks. Every farmer must keep the pesticides in a securely locked place. In both industrialised countries as well as in developing countries, there have been many accidents where children or others have been exposed to pesticides. In some cases, pesticides have been used for suicides.
Health risks caused by the use of pesticides: Persons involved in pesticide spraying, seed treatment, fumigation or soil disinfection will be exposed to vapour, drops of liquid, dust or fumes from the pesticide. Other persons close to the area where pesticides are weighed or measured before use or who may be in the treatment area, can be exposed. Pesticide residue in insufficiently cleaned packaging materials and spraying equipment can be dangerous for children and others. The concentration of the pesticide is considerably higher before dilution. The inhalation of powder dust or fumes from spraying liquid can therefore be a considerable health hazard. The spillage of concentrated spraying liquid on the skin during dilution can be particularly dangerous. Diluted pesticide can be absorped through skin during the spraying. The skin adsorption can thus take place over a much longer period of time, and the amount of pesticide liquid taken up can be considerable.
Uptake in the body: The most important uptake routes are through the skin and the respiratory passages. Improper handling of pesticides can cause the pesticide to be sprayed into the mouth and thus to be taken up in the lungs or the digestive organs. The extent of skin uptake depends on the fat solubility of the pesticide. Organic phosphor pesticides and chlorinated hydrocarbons are fat soluble and are easily adsorpted through skin. The extent of skin adsorption depends on the solubility products found in the pesticide. Warm and sweaty skin has a higher adsorption than dry skin. When the pesticide has been taken up in the body the blood veins will carry it through the body. Some pesticides can cause local damage to lungs, skin or eyes. Other pesticides can cause damage to internal organs such as the kidneys and the liver.
Symptoms of poisoning: Poisonous compounds disturb the natural biochemical processes in the body. Such processes can tolerate some strain before they are damaged. The body can tolerate small poisonous quantities, but when exposed to bigger doses, the metabolism will be hindered and symptoms of poisoning will appear. There are hundreds of different types of pesticides, and the symptoms of poisoning vary considerably. Common symptoms are headaches, dizziness, limpness, nausea, vomiting, sweat, flow of spit or tears, diminished pupils or visual disorders. In more serious cases there may be chest pains, dyspnea, convulsions, paralysis and unconsciousness.
First aid in the event of poisoning: Any suspicion of poisoning must be regarded as poisoning until there is proof to the contrary. See a doctor or other medical personnel as soon as possible. In the event of serious poisoning the following general first aid measures may be taken:
· Take the patient away from the pesticide area and into fresh air.
· Make sure that the respiratory passages are unobstructed.
· Put the patient in a lateral position.
· Administer artificial respiration if necessary
· Remove polluted clothing. Wash and rinse any parts of the body which may have come into contact with the pesticide. Rinse the eyes with running water.
· If the patient has swallowed poisonous material and is conscious, provoke vomiting. If the patient has been poisoned by strong acids, lye or petroleum distillates, vomiting must not be provoked.
· Call for medical assistance and explain what substance has caused the poisoning.
Protective equipment: The purpose of personal protective equipment is to protect skin, eyes, respiratory passages and the body as a whole against pesticides. As long as clothes are changed frequently, and always in the event of spillages, all-covering cotton overalls can offer equally good protection against skin exposure as clothing made of impregnated materials. Intact, unbroken gloves made of neoprene rubber or PVC plastic offers protection for the hands. It is very important that no pesticide is spilt into the gloves, as this increases the risk of uptake and allergic reactions. A face screen protects the face against sprays when diluting the pesticide. A gas mask or other respiratory protection is required during spraying of the most poisonous pesticides under conditions when there is a lot of wind drift or dusting.
By mist spraying of hazardous pesticides the use of respiratory protection with filters is necessary. Many places may have limited access to advanced protective equipment such as gas masks, but the importance of simple protective equipment such as special clothing, gloves etc. should always be stressed.
Pesticide residues in food and fodder must be avoided. Whenever food is exported on a large scale, the pesticide residue problem must be dealt with in particular. A small number of farmers can destroy major export projects if pesticide residues are detected in the food by the importing country.
The drinking water resources must never be sprayed with pesticides or used for dumping pesticide wastes, or for cleaning the spraying equipment. A protective zone of a minimum of 20 to 50 metres should be established around the drinking water resources, including the tributaries.