Pesticides Residues in Agricultural Soils and Its Health Assessment for Humans in Cameron Highlands, Malaysia

Soil contamination is one of the sensitive issue in agricultural region of Cameron Highlands, Malaysia, which is a largest vegetable producer. Organochlorine pesticides (OCPs), organophosphorus pesticides (OPPs) and pyrethroids pesticides (PYRs) concentrations were measured in 35 soil samples of selected crops. Among OCPs, the average concentration in the soil of these crops grown was in the order of cauliflowers > cabbage > broccoli > lettuce > celery > spinach > mustard, while for OPPs; spinach > broccoli > cabbage > cauliflower > celery > lettuce > mustard > and for PYRs it was broccoli > cabbage > cauliflower > spinach > mustard > celery > lettuce. For risk assessment life time average daily dose (LADD) of OCPs, OPPs and PYRs for adults were calculated at 2.1 x 10 -7 -1 x 10 -6 mg kg -1 d -1 , 1.46 x 10 -11 -3.6 x 10 -10 mg kg -1 d -1 and 1.28 x 10 -12 -3.42 x 10 -12 mg kg -1 d -1 meanwhile for children 5.3 x 10 -8 -2.7 x 10 -7 mg kg -1 d -1 , 3.8 x 10 -11 -9.4 x 10 -10 mg kg -1 d -1 and 8.8 x 10 -12 -1.6 x 10 -10 mg kg -1 d -1 . The hazard quotient (HQ) was 1 indicating less health risks for humans. Principal Component Analysis (PCA) indicates a strong correlation of high pesticides residual concentration of the soil of crops (cauliflower, cabbage and broccoli) with soil properties (pH and organic content) thus influencing its mobility and persistence whereas for other crops soil the decrease residual concentration might be related to crop type, rotation, roots exude, rhizosphere effect, or a rapid disappearance of pesticides after application.