Pesticides & Health

Definition of Pesticide

Any substance intended to prevent, destroy or repel insects, rodent, nematodes, fungi, weeds, microorganisms or any form of life declared to be a pest.

Pesticides & Health

Many pesticides are toxic and since their first use it has been known that they present a risk to human

WHO report estimated that there are 3 million severe human pesticide poisoning in the world each year, of which approx 220,000 are fatal

The causes of Acute Pesticide Poisoning (APP) presented are based on the following case classification, which depends on the circumstance of exposure:

Occupational: Exposure to pesticides during work or processes derived from the latter, such as manufacture, formulation, storage, transportation, application, and final disposal.

Accidental: Exposure to pesticides that occurs unintentionally and unexpectedly.

Intentional: Exposure to pesticides with intent to cause harm. This includes suicide attempts, suicides, and homicides.

Acute Pesticide-Related Illness The most obvious effect on human are

acute poisoning which occur shortly after an exposure to a pesticide

Common in developing countries where regulations are less strict and where farmers have insufficient access to training, application equipment & appropriate protection clothing

It is estimated that about 3% of exposed agricultural workers suffer from an episode of acute pesticide poisoning (APP) every year.

Notification is needed to limit all adverse effects from regulated pesticides

A case is characterized by an acute onset of symptoms that involve one or more of the followingSystemic signs & symptoms (include resp, GI, allergic

& neurological S & S)Dermatological legionsCharacteristic eye injuries

Lab criteria for Dx:

1. Measurement of the pesticide & its metabolites in blood and urine

2. Measurement of a biochemical response to the pesticide (e.g. cholinesterase level)

• Cholinesterase depression is defined as 30% depression from base line, or cholinesterase below lab normal range

• Or if pre-exposure level are not available, serial post-exposure testing done (e.g. 2wk & 4wk post-exposure testing show a gradual increase in cholinesterase by 1% & 2%, respectively over the level at initial testing)

Lab criteria for Dx:

3. Environmental tests for the pesticide (e.g. analysis of suspected liquid)

4. Pesticide detection on clothing or equipment used by the case subject

5. Biologic evidence of exposure (e.g. response to administration of an antidote such as Vit K or repeated doses of atropine)

Severity Index

Purpose: to provide simple, characterized criteria for assigning severity to cases of acute pesticide-related illness

It takes into accounts the following S & S Whether medical care was sought Whether the individual was hospitalized Whether there was lost time from work

Severity Index

S 1 Death

S 2 High severity illness or injury Life threatening & typically requires Tx Involve hospitalization to prevent death S & S include coma, cardiac arrest, RF or resp dep Loss of time (> 5 days) from work Permanent functional impairment

Severity index

S 3 Moderate severity illness or injury Less severe illness often involving systematic

manifestations Generally, Tx was provided Ability to return to normal functioning without any

residual disability Less time is lost from work (> 3-5 days)

S 4 low severity illness or injury: Often manifested by skin, eye or upper resp irritation It may include fever, headache, fatigue or dizziness Resolves without Tx Minimal lost time (< 3 days) from work

Chronic effects:

1. Organophosphate Pesticides (OPs): Most widely used worldwide Among the most acutely toxic of all

pesticides It is associates with:

Neuroroxicity Increase incidence of myopia Increase incidence of ch. fatigue syndrome

Diminished human fertiltiy

A recent study on agricultural workers in Mexico who were exposed to OPs, showed that 75% of agric. Workers’ semen samples were classified as having poor fertility potential compared to 4% of non-exposed men from the same region

2. Endocrine Disrupting Chemicals: Act by either mimiking natural hormones or by interfering

with their functions

It is associated with:

- decline in sperm count in many countries

- increase of 55% of incidence of testicular cancer (1979 - 1991) in England & Wales

- increase in prostrate cancer

- increase in breast cancer in women

3. Persistent Organic Pollutants (POPs):

Groups of chemicals which are very resistant to natural breakdown processes, & may persist for years

Highly toxic & bioaccumulate in the fatty tissues

Interfere with sexual characteristics

Affect immune & nervous systems

4. The “Cocktail” effect:

Human are exposed to mixtures or “cocktail” of pesticides

Research on their toxicological impacts is limited

Some research has shown that pesticide can act additively or synergistically when in combination (e.g. synergistic neurotoxicity)

5. Pesticides which cause cancer

Epidemiological evidence suggests significantly higher cancer incidence among farmers & farm workers in the US & Europe than among non farm workers in some areas

An estimate of no. of cases of cancer in the US due to pesticides is about 12,000 cases per year

The Status in the UAE

Data are not available regarding no. of cases with pesticide-related illness or death

The Status in Al-Ain:

Any case of ac. Pesticide-related illness will be referred to Al-Ain Hosp and treated accordingly

Two pesticide applicators died few years ago most probably from exposure to pesticide, but investigations were not carried out to know the cause of death

There is no registeration of APP cases either in hospitals or in in the Municipality, there are different reasons for that, the most important being:

1) the person with APP does not seek care in health centers (by lack of knowledge of the signs and symptoms, fear to lose their employment, difficulty of access to health services, mild cases that do not seem to require care)

2) the person with APP seeks medical care but diagnosis is not done or not reported correctly

3) the person intoxicated seeks medical care, is

diagnosed and reported, but for administrative reasons the report is not registered

3 years ago, the municipality has started to establish an occupational clinic in corporation with the Preventive Medicine Purpose:

To assess the medical fitness of workers To regularly check-up all workers for any S & S of ac

pesticide-related illness To measure their cholinesterase level every month To provide courses of firstaid for each worker

The project was – unfortunately – not completed!!

The Status in Al-Ain:

The Status in Al-Ain:

Recently, a workshop was provided to all workers who are dealing with pesticides about the safe use of pesticides

Thank you!