Assessment of multiresidue pesticides in agricultural soils from ledang, Malaysia and related potential health risks

Abstract

The concentration levels of organochlorine and organophosphorus pesticide residues in agriculture soils from paddy field were successfully investigated. Residues were isolated using the Soxhlet extraction method, following a clean-up process (SPE Florosil) and a final determination of targeted compounds performed by using a gas chromatography electron capture detector. The concentration levels ranged from 0.98 to 3.60 μg/kg of dry weight during the period of study. Only five compounds were found less frequent <50% out of 56 soil samples. The physical properties of soil samples were identified as acidic (pH 4.8 to 5.4), organic content (6.4 to 7.8%) and the particle size was dominated by the sandy fraction type. Hierarchical agglomerative cluster analysis was used to discriminate eight stations into two groups (C1: 1-4 and C2: 5-8) at Dlink/Dmax × 100 < 83. Three components (PC1- PC3) explained about 89.30% of the total variance in the data sets from an eigen value of >1. The occurrences of HCH isomers, DDE, heptachlor epoxide and endosulfan compounds were recognized as the main contributors of pollutant in this area. Hazard quotient for adults and children health risks were calculated in the range of 8.57 × 10-9 - 5.23 × 10-5 and 4.44 × 10-8 - 2.71 × 10-4, respectively. It was reflected that the present status is below than the acceptable risk level, HQ < 1. Incremental lifetime cancer risk (ILCR) was recorded slightly higher for children ranging from 1.73 × 10-8 to 4.22 × 10-11 compared to the risk toward adults from 3.34 × 10-9 to 8.15 × 10-12. It would be interesting to observe the details of the depth profile analysis to understand the mobility of pesticide residues for future study. © 2018 Technoscience Publications. All rights reserved.