Metal transfer and related human health risk assessment through milk from cattle grazing at an industrial discharge area

ABSTRACT

The water bodies within industrial areas are often used for the disposal of effluents leading to metal contamination in water, soil, and vegetation. However, the impact of metal enrichment in the food grown in these areas has not been much explored. The present study investigates the food chain contamination of eight metals (Al, Cd, Cr, Cu, Fe, Mn, Pb, and Zn) in the milk from the cattle grazing on a shallow lake bed within the industrial town of Ranipet, India, and associated health risk from the consumption by adults and children. It also considers the possible sources of metals into the cattle from water, forage, and soil. The total number of cattle grazing in the study area was identified, along with their average daily intakes. The total milk yield from these cattle and the milk consumption rates were identified from surveys conducted among cattle owners and milk buyers. The primary sources of all the metals, except Al are forage; whereas for Al, it is the soil. The projected milk consumption pattern indicates that 531 children and 1279 adults drinking contaminated milk are at considerable risk. The hazard indices ranged from 0.86 to 2.74 for children, and 0.35 to 1.13 for adults. The Cancer Risk values for Cd and Cr were above 10⁻⁴ for adults and children, signify serious health risk. The analyses of tail switch hair samples indicated that cattle are also environmentally exposed to metals indicating their subclinical effect. Hence, the study substantiates that soil can be a potential source of metals in the food chain, and apprises stringent quality control and monitoring food chain contamination from milk in industrial belts.

KEYWORDS:

• Cancer risk
• cow milk
• mass balance
• metal contamination
• urban waterbody

Acknowledgments

The authors acknowledge the help of Department of Science and Technology-Science and Engineering Research Board [DST-SERB] for the financial support provided for this study and Vellore Institute of Technology [VIT] for providing necessary laboratory facilities to carry out this work.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The switch-tail hair metal concentrations and risk estimation are not included in the manuscript and can be found at: 10.6084/m9.figshare.16947343.v1. All other data are available from the authors upon reasonable request.

Ethics approval

All of the experiments were carried out in compliance with the standards of international, state, and/or institutional animal care and use guidelines. There are no experiments involving human participants in this article.

Supplemental data

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Additional information

Funding

The research was financially supported by Department of Science and Technology-Science and Engineering Research Board [DST-SERB] under project [DST/EMR/2016/006662].