The effect of pesticide on the activity of serum cholinesterase and current perception threshold on the paddy farmers in the Muda agricultural development area, MADA, Kedah, Malaysia.
BACKGROUND
The aim of this study was to find out the indicator as a marker of person who are exposed to pesticides (organophospate). Up to now the serum cholinesterase is used as a marker. This new method will not taking blood vein since this be the obstacle in conducting research in a rural area.


METHODS
A cross sectional study was conducted to investigate the effect of pesticide exposure on the activity of serum cholinesterase (ChE) and current perception threshold (CPT). The samples are 60 paddy farmers (exposed group) and control group taken from the office of Muda agricultural area of Kedah in 19 do not expose to pesticide. The CPT values measured using a portable constant current electric nerve stimulator, Neurometer CPT/Eagle (Neurotron Incorporated, Baltimore, USA). Assessments carried out by one examiner on the index finger (median digital nerve) and the great toe (peroneal digital nerve). The current used are 3 neuroselective frequency range 2000 Hz, 250 Hz, and 5 Hz. The serum cholinesterase activity measured spectrophotometrically using cholinesterase inhibition test kit CHE MHE 1,144729.


RESULTS
It was significantly evident that the serum cholinesterase activity noted reduced among the paddy farmers (p = 0.014). The CPT values were significantly elevated for the 2000 Hz frequency range for both the measurement sites (index finger p < 0.0001 and great toe p < 0.0001). For the 250 Hz frequency range CPT values were significant only for the index finger (p = 0.012). However there was no significant difference for the 5 Hz frequency range. There was also a significant correlation (negative) between CPT values and serum cholinesterase activity more for the 2000 Hz frequency range (index finger r = 0.672, p < 0.0001 & for great toe r = 0.736, p < 0.0001). The results were suggestive of subclinical impairment of distal axonopathy considering the fact only 25% of the farmer showed clinical manifestation of numbness.


CONCLUSIONS
The selective involvement of the large diameter sensory fibres (250 Hz and 2000 Hz) were reflective of toxic peripheral neuropathy. Neurometer CPT/Eagle used as indicator for detecting the effect of pesticide instead of using cholinesterase enzyme activity.
Husin
L S
LS
Department of Biomedical Sciences, School of Allied Health Sciences, Universiti Kebangsaan Malaysia.
Uttaman
A
A
Hisham
H J
HJ
Hussain
I H
IH
Jamil
M R
MR
D000328:Adult; D000368:Aged; D000383:Agriculture; D002802:Cholinesterases / Q000097:blood*; D006801:Humans; D008296:Malaysia; D008875:Middle Aged; D010575:Pesticides / Q000494:pharmacology*; D012684:Sensory Thresholds / Q000187:drug effects*
D010575:Pesticides; D002802:Cholinesterases