Human health risks of trace metals through the dietary intake of potato tubers and exposures of potato cultivating soils: A case study of Mymensingh district, Bangladesh

Abstract

Background

Trace metal contamination in soil and farm products is common in Bangladesh, which enhances public awareness. Most of the studies in our country ignored potential human health risks from different routes of exposures to trace metals present in potato tubers and potato-growing soils.

Objectives

The study objectives were to measure trace metals pollution level in soils, and to evaluate human health risks due to dietary intake of potato tubers, as well as ingestion, dermal and inhalation exposures of potato-cultivating soils of Mymensingh district, Bangladesh.

Methods

An atomic absorption spectrophotometer was used to determine Cd, Ni, Pb, Cr, Cu, Zn, Fe, Co, and Mn in the extract of soils and potato tubers. The study employed contamination factor (CF), pollution load index (PLI), and potential ecological risk index (PERI) to evaluate the level of soil pollution. Non-carcinogenic and carcinogenic human health risks were assessed based on calculated Hazard Quotient and Cumulative Incremental Lifetime Cancer Risk (∑ILCR), respectively.

Results

A threshold of "moderate contamination" (1.0 ≤ CF < 3.0) can be assigned to certain soil sampling sites based on the computed CF values for Ni, Cd, and Pb. On the contrary, the calculated PERI indicated that the soils of potato-cultivating regions of the study area are ecologically free from pollution. Regarding non-cancer risks, the measured hazard quotient (HQ) values for all avenues of exposure to trace metals were below 1.0, indicating that they are safe for human health. On the other hand, the calculated incremental lifetime cancer risk (ILCR) values for Ni in 83.3% of potato tuber samples for both sexes and Cd in 58.3% of males and 91.7% of females had scores greater than 1.00E-04, which indicates carcinogenic risks to adult humans. However, the estimated mean ∑ILCR for males and females in various routes of exposure showed a decreasing trend in the order of ILCR_Oral (potato ingestion) >ILCR_{Soil ingestion} >ILCR_{Dermal adsorption} >ILCR_{Soil inhalation}.

Conclusion

The agricultural soils of Bangladesh are becoming progressively degraded due to multiple contamination causes along with trace metals. The investigation recommended that future traceability efforts focus on locating possible sites of entry for toxic metals into the nation's food supply chain.