Dietary exposure and risk assessment of polychlorinated biphenyls to artisanal fishermen and fish vendors: A case study of Dar es Salaam

Abstract

Background

Fish is one of the main sources of food and income in Tanzania, with 25% of the population depending on fishing activities as a source of food, income, and employment. But fish consumers are vulnerable to exposure to toxic pollutants including PCBs due to the lipophilic nature of the pollutants which accumulate in fish.

Results

The estimated mean NDL PCBs concentration level was 0.84 ng/g w/w and the mean fish consumption rate among fishermen was 0.4 kg/day. Mean exposure of the fishermen and fish vendors to total PCBs ranged between 9.62 and 36.12 ng/kg bw/day depending on the estimation scenario (lower bound/upper bound) for both normal and higher fish consumers. The general population exposure to total PCBs was 0.4 and 0.8 ng/kg bw/day in lower-bound and upper-bound estimation scenarios respectively. The estimated lifetime carcinogenic and non-carcinogenic hazard indices from intake of estimated total PCBs by fishermen and fish vendors exceeded the recommended tolerable daily intake, TDI, raising serious concerns for adverse health effects to fishermen and fish vendors. However, for the general population, there was no concern for any potential health effects as the estimated hazard indices were far below the recommended levels for intake of total PCBs.

Conclusion

The exposure levels of fishermen and fish vendors to PCBs via consumption of Rastrelliger kanagutra (Indian mackerel) in Dar es Salaam are high enough to course serious health concerns, especially for high fish consumers and efforts should be taken to encourage diversification of fish species intake.