Friday, June 6, 2008

Pesticides in Farming DNA damage among Punjab farmers high: Study

DNA damage among Punjab farmers exposed to mixtures of pesticides is too high to be ignored.
These findings are part of a study made by Dr Raminderjeet Kaur, a research fellow working under the guidance of Dr Satbir Kaur of the Department of Human Biology at Punjabi University.
The study, “Assessment of genetic damage in workers occupationally exposed to various pesticides in selected districts of Punjab,” examined DNA fragmentation from blood cells.
The researcher collected samples twice after six months between December 2003 and January 2006. The first blood samples were collected from 210 farmers after one day of intense spraying of pesticides. In the second sample, 60 workers were selected from the sub-group who showed DNA damage six months after the first samples were taken during a low or no-spraying period to determine the frequency of spontaneous DNA repair.
The study reveals that the DNA fragmentation was found in 36 per cent of the freshly exposed group in the first sampling and among 25 per cent of the “followed up” cases. The highest DNA damage was found among users of herbicides followed by organophosphates and then chlorinated hydrocarbons.
The study added the confounding factors such as variable duration of exposure, age, smoking, drinking and dietary habits which were expected to modulate the damage, were instead found to have no significant effect on DNA fragmentation.
The researchers observed less than 10 per cent workers never used any protective clothes or equipment and typically handled highly toxic chemicals with bare hands and without masks. There was a complete unawareness of the extreme dangers to which they were exposing themselves. It was even found that pesticide containers were being used as kitchen containers and vessels.
“The situation urgently calls for mass education programme and mandatory provision of protective gear and warnings by pesticide companies as well as reduction in the use of pesticides failing this a epidemic of genetic damage diseases, particularly cancer is likely,” the study added.

DNA damage in the Punjabi farmers

ASSESSMENT OF GENETIC DAMAGE IN WORKERS OCCUPATIONALLY EXPOSED TO VARIOUS PESTICIDES IN SELECTED DISTRICTS OF PUNJAB
RAMINDERJEET KAUR, Department of Human Biology, Punjabi University, Patiala
Key Words: Pesticides, Comet Assay, Genetic Damage, Agriculture workers, Comet tail length.
Abstract:
Pesticides are unavoidable in agriculture as they are useful in enhancing crop productivity. Despite the beneficial affects associated with their use, many of them form a potential hazard to human and mother nature. The present study has been conducted with a view to investigate the potential genetic hazards associated with occupational exposure to various pesticides in selected districts of Punjab. In order to determine possible genotoxic effects in agricultural workers, blood samples were taken from 210 workers divided into three groups i.e. group A (orchard sprayers), group B (vegetable sprayers) and group C (wheat, paddy, cotton etc. sprayers) one day after spraying during intense spraying activity. Seventy samples for each group A, B and C and fifty samples for a control group of normal healthy age matched individuals were taken. Twenty cases each from group A, B and C were selected for a follow up study amongst those workers who showed DNA damage. Second sampling of follow up cases was done during a period of null or minimum spraying 5-6 months after first sampling. Genetic damage was assessed using alkaline single cell gel electrophoresis assay. One hundred cells were examined for each individual and measurements were recorded with the help of ocular micrometer. Two comet parameters viz. head diameter and tail length were measured in micrometers (µm) and a third one i.e. T/N index was derived from these parameters. A fourth parameter i.e. the frequency of cells showing migration was calculated by scoring damaged cells and total cells on the slide. Highly significant increase in genetic damage was observed in exposed group compared to control. Workers of all the three exposed groups showed interindividual as well as intra-individual variations in four comet parameters while control group subjects showed quite homogenous results. The frequency of genetic damage was significantly reduced in the follow up cases of all the three groups. Duration of exposure did not significantly influence the level of DNA damage in three exposed groups as no correlation between genetic damage and duration of exposure was found. Herbicides were found to show more deleterious effect in comparison to other classes of pesticides. No significant increase in genetic damage was seen with the increase in age of the workers. No correlation was observed between smoking and genetic damage in the three groups. Non-vegetarians and alcoholics showed slightly higher incidence of genetic damage than vegetarians and non-alcoholics but the differences were non-significant. With respect to the use of protective clothing and devices, individuals exhibited lower values of comet parameters than those who did not take any safety measure, but the differences were statistically non-significant .