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.
RESULT: 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.
CONCLUSION: 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.