Fig 1.
Box and whisker’s plot of pesticide residues in sediment samples from upper stretch of river Ganga.
Fig 2.
Box and whisker’s plot of pesticide residues in sediment samples from middle stretch of river Ganga.
Fig 3.
Box and whisker’s plot of pesticide residues in sediment samples from lower stretch of river Ganga.
Fig 4.
Correlation between total organic carbon and total pesticide concentration in sediment samples collected from three stations of river Ganga (r2 = 0.8).
Fig 5.
Principal component plot of pesticide residues in sediment samples from river Ganga.
The determination of carcinogenic and non-carcinogenic risk associated with pesticide exposure from sediments includes three routes. The non-carcinogenic risk estimation from the three stations (Tables 1, 2 and 3) were below the reference levels (USEPA) for each studied pesticide, therefore these contaminants are unlikely considered to pose potential risk to human health [69]. According to the USEPA, guidelines if the estimated CDI value of pesticide exceeds oral reference dose (S3 Table, USEPA) value is supposed to pose adverse health impact or non-carcinogenic risk to human health. The estimated CDI value for each pesticide showed that children are at higher risk than adults. Ogbeide et al. [34] have reported similar results for CDI values from Illushi River, Ogbesse River and Owan River of Nigeria. Carcinogenic risk from the exposure of pesticides in sediments was below the threshold limit of 10−6 (USEPA) indicating no observed risk for both adults and children population groups at each station. Estimated results for non-carcinogenic and carcinogenic risk showed, pesticide exposure from the inhalation route has higher potential to cause risk in adults and children than by other two routes. Further, the study also clarifies that there is a higher potential of cancer risk through multiple exposure routes in children than in adult population groups.
Table 1.
Estimation of Chronic daily intake (CDI) and hazard quotient (HQ) for pesticide residues in sediment from middle stretch.
Table 2.
Estimation of Chronic daily intake (CDI) and hazard quotient (HQ) for pesticide residues in sediment from Upper stretch.
Table 3.
Estimation of Chronic daily intake (CDI) and hazard quotient (HQ) for pesticide residues in sediment from lower stretch.
Table 4.
Risk assessment of pesticide residues in sediment samples based on toxic units calculation.