PESTICIDE POISONING

Most pesticides can cause poisoning after being swallowed, inhaled, or absorbed through the skin.
Pesticide poisoning occurs when chemicals intended to control pests affect non-target organisms such as humans, or food and agric facilities etc.
There are basically  three (3) types of pesticide poisoning.

A.)  The first of the three is a single and short-term very high level of exposure which can be experienced by individuals who commit suicide, as well as pesticide formulators and others who accidentally swallows/ingests  pesticide.

B.)  The second type of poisoning is long-term high-level exposure, which can occur in pesticide formulators and manufacturers.

C.)  The third type of poisoning is a long-term low-level exposure, which individuals are exposed to from sources such as pesticide residues in food as well as contact with pesticide residues in the air, water, soil, sediment, food materials, plants and animals

The fact is that the properties  that make pesticides deadly to pests can sometimes make them poisonous to humans too. Most serious pesticide poisonings result from the organophosphate and carbamates types of pesticides, particularly when used in suicide attempts and, when swallowed accidentally, in occupational settings.
Organophosphates include malathion, parathion, fenthion, dursban, diazinon, chlorpyrifos, and sarin. Some of these compounds are derived from nerve gases.
Also, Carbamates include aldicarb, carbaryl, carbofuran, fenobucarb, and oxamyl.
Pyrethrins and pyrethroids, which are other commonly used insecticides, are derived from flowers and usually are not very poisonous to humans.

As mentioned earlier, many pesticides can cause poisoning after being swallowed, inhaled, or absorbed through the skin. Some insecticides are odorless, thus the person is unaware of being exposed to them. Organophosphate and carbamate insecticides make certain nerves “fire” erratically, causing many organs to become overactive and eventually to stop functioning. Pyrethrins can occasionally cause allergic reactions.
Pyrethroids rarely cause any problems.

EPIDEMIOLOGY OF PESTICIDE POISONING
Pesticide poisoning is a large-scale public Health problem, especially in developing countries like Nigeria.
"Most estimates concerning the extent of acute pesticide poisoning have been based on data from hospital admissions which would include only the more serious cases.
However, latest estimate by a WHO task group indicates that there may be 1 million serious unintentional pesticide poisonings each year and in addition about 2 million people hospitalized for suicide attempts with pesticides. This necessarily reflects only a fraction of the real problem. On the basis of a survey of self-reported minor poisoning carried out in the Asian region, it is estimated that there could be as many as 25 million agricultural workers in the developing world suffering an episode of poisoning each year." According to statistics In Canada in 2007 more than 6000 cases of acute pesticide poisoning occurred. Estimating the numbers of chronic poisonings worldwide is more difficult.

SIGNS AND SYMPTOMS  OF PESTICIDE POISONING
These may include eye tearing, coughing, heart problems, and breathing difficulty.

PREVENTION OF PESTICIDE POISONING
Accidental poisonings can be avoided by:
1. Proper labeling and storage of containers.

2. Wearing protective covering when handling or applying pesticides, exposure can be significantly reduced by protecting certain parts of the body where the skin shows increased absorption, such as the scrotal region, underarms, face, scalp, and hands.  

3. Using chemical-resistant gloves has been shown to reduce contamination by 33–86%.

4. Control of accessibility to very toxic pesticides and other chemicals by government:  This method would help in the prevention of acute pesticide poisoning, concerning both accidental death and suicides.
The pesticides that are most toxic to humans, if restricted, has the possibility to reduce deaths.

5. There could also be designated locations in rural living areas and cities used to safely store toxic pesticides in order to gain control over usage.

DIAGNOSING PESTICIDE  POISONING

The diagnosis is based on symptoms, blood tests, and a description of events surrounding the poisoning.

Most pesticide-related illnesses have signs and symptoms that are similar to common medical conditions. So a complete and detailed environmental and occupational history is essential for correctly diagnosing a pesticide poisoning. A few additional screening questions about the patient's work and home environment, in addition to a typical health questionnaire, can indicate whether there was a potential pesticide poisoning.

If one is regularly using carbamate and organophosphate pesticides, it is important to obtain a baseline Cholinesterase test. Cholinesterase is an important enzyme of the nervous system, and these chemical groups kill pests and potentially injure or kill humans by inhibiting Cholinesterase.
If one has had a baseline test and later suspects a poisoning, one can identify the extent of the problem by comparison of the current Cholinesterase level with the baseline level.

MANAGING PESTICIDE POISONING
As soon as pesticide poisoning is diagnosed the best step is to seek quick medical attention  in the nearest hospital.
Also, pecific treatments for acute pesticide poisoning are often dependent on the pesticide or class of pesticide responsible for the poisoning. However, there are basic management techniques that are applicable to most acute Pesticidal poisonings, including skin decontamination, airway protection, gastrointestinal decontamination, and seizure treatment.

Decontamination of the skin is performed while other life-saving measures are taking place. Clothing is removed, the patient is showered with soap and water, and the hair is shampooed to remove chemicals from the skin and hair. The eyes are flushed with water for 10–15 minutes.
Several drugs are effective in treating serious insecticide poisonings
-EHSadvisor

REFERENCES:

 Ramesh C. Gupta (28 April 2011). Toxicology of Organophosphate & Carbamate Compounds.

Denis Hamilton; Stephen Crossley (14 May 2004). 
Pesticide Residues in Food and Drinking Water: Human Exposure and Risks.

-Lewis A. Owen; Professor Kevin T Pickering; Kevin T. Pickering (1 March 2006). 
An Introduction to Global Environmental Issues.

Annalee Yassi (2001). Basic Environmental Health.

SPECIAL THANKS  TO WIKIPEDIA