Lasting effects of insecticides exposure

[Guest guest]

Hi all,

Below is an excerpt from an upcoming article from the Agricultural

Health Study to be published in Environmental Health Perspectives (which

is free online).

USE OF INSECTICIDES LINKED TO LASTING NEUROLOGICAL PROBLEMS FOR FARMERS

New research shows that farmers who used agricultural insecticides

experienced increased neurological symptoms, even when they were no

longer

using the products. Data from 18,782 North Carolina and Iowa farmers

linked

use of insecticides, including organophosphates and organochlorines, to

reports of reoccurring headaches, fatigue, insomnia, dizziness, nausea,

hand

tremors, numbness and other neurological symptoms. Some of the

insecticides addressed by the study are still on the market, but some,

including DDT, have been banned or restricted.

These findings will be available online in April, and published in the

June issue of " Environmental Health Perspectives " . The research is part

of the

ongoing Agricultural Health Study funded by the National Institute of

Environmental Health Sciences and the National Cancer Institute, two of

the

National Institutes of Health, and the Environmental Protection Agency.

" This research is really important because it evaluated the health

effects of agricultural chemicals as they were commonly used by farmers.

It's

different from previous studies that focused on pesticide poisoning or

high

dose exposures, for example when large amounts of a chemical were

accidentally spilled on the skin, " said Freya Kamel, Ph.D., a researcher

for the National Institute of Environmental Health Sciences (NIEHS).

The NIEHS researchers examined questionnaires completed by farmers on

lifetime exposure to herbicides, insecticides, fungicides, and

fumigants,

and their history of 23 neurological symptoms. Those who reported

experiencing more than 10 symptoms during the year prior to completing a

study questionnaire were classified as having high levels of symptoms.

Researchers found that nearly 3,000 participants had a high lifetime

exposure to insecticides -- that is, they used insecticides more than

500 days in their lifetime. Nearly 800 of these farmers reported more than

10

neurological symptoms compared to those using insecticides fewer than 50

days. The researchers found no significant association between

neurological

symptoms and other chemicals, including herbicides or fungicides, and

only a

weak association between fumigant exposure and neurological symptoms.

Some of the insecticides used by the licensed farmers over the past 25

years are no longer available commercially. DDT, a well known example of an

organochlorine, has been banned for use in the US since 1972.

Organophosphates, such as malathion, chlorypyrifos, and diazinon, have

been

banned or restricted for home and garden use in the US. However, some of

the pesticides examined, including carbaryl and some pyrethroids, are

available

to home gardeners, although in different formulations and in lower

concentrations, which may make them less hazardous.

" Because the participants in this study are telling us they have never

been previously diagnosed with pesticide poisoning or medically treated

for any

exposure to any pesticide, we are led to conclude that their symptoms

are

related to moderate lifetime exposure, " said Dr. Kamel.

" Most studies of this issue have sample sizes ranging from 50 to 100

participants, making it hard to understand the detailed relationship

between

exposure and health effects. The large size of this study gives it great

statistical power, " said Dr. Kamel.

The AHS (http://www.aghealth.org/) is designed to investigate the

effects of

environmental, occupational, dietary, and genetic factors on the health

of

the agricultural population. The study will provide information that

agricultural workers can use in making decisions about their health and

the

health of their families.

NIEHS looks at factors in the environment that may be harmful to human

health. More information about NIEHS and the Agricultural Health Study

can

be found at http://www.niehs.nih.gov.

##

This NIH News Release is available online at:

http://www.nih.gov/news/pr/apr2005/niehs-28.htm.

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