Polychlorinated biphenyls (PCBs) residues in commercial pasteurized cows\u2019 milk in Tehran, Iran

Reza Ahmadkhaniha,Ramin Nabizadeh Nodehi,Hassan Mohammadi Aghamirloo,Noushin Rastkari

doi:10.1186/s40201-017-0278-y

Reza Ahmadkhaniha, Ramin Nabizadeh Nodehi + Show 2 more

Open Access

https://doi.org/10.1186/s40201-017-0278-y

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Abstract

BackgroundTo date, despite the facts that pasteurized milk is the most consumed dairy product in Iran and its consumption has increased almost two fold during the last 10 years, no data are available concerning the concentrations of polychlorinated biphenyls (PCBs) in commercial cow milk in Iran market.MethodsThis study designed to determine the levels of PCBs in these products and to assess population exposure to PCBs by estimating the daily intakes. Pasteurized cows’ milk samples (10 brands) were collected from local markets at two different seasons and analyzed using sensitive and reliable methods.ResultsBased on the results all the indicator PCBs were detected and quantified in all of the samples, the mean ± SD concentration for the sum of the six congeners was 18.92 ± 14.36 ng g−1 fat. None of the samples surpassed the provisional value established by the EU of 40 ng g−1 fat. The sum of dioxin-like congeners, expressed as WHO-TEQ was 0.492 pg/g of fat which was considerably lower than the defined limit 3 pg/g fat, set for cow’s milk. Furthermore, a similar DL-PCBs profile as other studies was found for analyzed samples. The results indicated that concentrations of DL-PCBs were very low, and all of milk samples were compliant with EC legislation. In addition, seasonal variations were not observed for DL- and NDL-PCBs levels (p values >0.05).ConclusionsThe estimated dietary intake for target population was 0.06 pg TEQ/kg of body weight/day, much smaller than the amounts declared by the World Health Organization as tolerable daily intake.

Highlights

To date, despite the facts that pasteurized milk is the most consumed dairy product in Iran and its consumption has increased almost two fold during the last 10 years, no data are available concerning the concentrations of polychlorinated biphenyls (PCBs) in commercial cow milk in Iran market
Considering that up to now, no study has been conducted in Iran for determining PCBs levels in commercial pasteurized milk, the aim of this research is to determine the levels of PCBs in commercial cow milk consumed in Tehran and to assess population exposure to PCBs by estimating the toxic equivalents (TEQ)
Determination of the total TEQ were carried out based on assumption that all non-detected (n.d.), as well as smaller than limit of quantification values (

Summary

Introduction

Despite the facts that pasteurized milk is the most consumed dairy product in Iran and its consumption has increased almost two fold during the last 10 years, no data are available concerning the concentrations of polychlorinated biphenyls (PCBs) in commercial cow milk in Iran market. Polychlorinated biphenyls (PCB) make up a highly toxic group of pollutants that has widely spread in the environment. Many of human activities are the main causes of this kind of pollution and many evidences about adverse biological and toxic effects of PCBs have been found. The other group of PCBs which is comprised of six congeners (including PCB28, PCB52, PCB101, PCB138, PCB153 and PCB180) named “indicator PCBs” and usually are selected as suitable markers for PCBs pollution studies [3]. PCBs can be released into the environment and enter the food chain by means of the manufacturing and industrialized processes, daily usage of synthetic products, waste disposal and other human activities [5, 6]. Previous studies have shown that food is a major route of human exposure to these compounds which are lipophilic and have the propensity to bio-accumulate in biota [7,8,9]

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