Investigation of heavy metal contents in Cow milk samples from area of Dhaka, Bangladesh

Md Iftakharul Muhib,Muhammed Alamgir Zaman Chowdhury,Nusrat Jakarin Easha,Mohammad Latiful Bari,Mashura Shammi,Masaaki Kurasaki,Zeenath Fardous,M Khabir Uddin,Md Mostafizur Rahman,Md Khorshed Alam

doi:10.1186/s40550-016-0039-1

Abstract

Cow milk is considered as one of the responsible food sources contaminated with heavy metals. The objectives of the study were to assess the content of selected metals in cow milk and its associated human health risks in the food chain of Bangladesh. A total of 90 cow milk samples of Branded, Dairy and Domestically produced milk were collected randomly from different sources of Savar Upazila in Dhaka area. Cadmium (Cd), chromium (Cr), lead (Pb), manganese (Mn), copper (Cu) and iron (Fe) contents in collected milk samples were determined using Flame Atomic Absorption Spectrometry (FAAS). To ensure quality control, one of the best quality control parameters i.e. recovery test; from eight various sample digestion methods were used. The Hazard Quotient (HQ) and Carcinogenic Risk (CR) values were also calculated. From the results, it was found that, the orders of heavy metal content in brand, dairy and domestic cow milk were Cr > Fe > Cu > Mn > Cd > Pb, Cr > Fe > Mn > Cu > Cd > Pb and Fe > Cr > Mn > Cu > Cd > Pb, respectively. Among the six metals, only Cr showed to exceed the highest Estimated Daily Intake (EDI) rate (for brand cow milk: 0.413 mg/day, dairy farm cow milk: 0.243 mg/day, domestic cow milk: 0.352 mg/day),and the comparison percentages of calculated values per permeable values were as follows; 206.5 % for brand cow milk,121.5 % for dairy farm cow milk and 176.0 % for domestic cow milk. Hazard Quotients (HQ) values and Carcinogenic Risk (CR) values were found within the acceptable level. Although, the metal content in sampled cow milks were within the safe limit, the potential human health risks cannot be neglected for the regular/long time consumption of heavy metal contained cow milk.

Highlights

Cow milk is considered as one of the responsible food sources contaminated with heavy metals
The milk samples were classified according to their collection sources as (i) the popular packaged cow milk was considered as Brand milk (33 samples), (ii) the dairy farm milk (30 samples) collected from the available dairy farms and (iii) the milk samples collected from the small household farmers as domestic cow milk (27 samples)
Average concentrations of trace metals among the branded cow milk samples had shown a descending order of Cr>Fe>Cu>Mn>Cd>Pb (Fig. 3)

Summary

Introduction

Cow milk is considered as one of the responsible food sources contaminated with heavy metals. Milk has a positive influence on human health It is considered as nearly complete food since they are good source of proteins, fats, vitamin supplements and major minerals (Enb et al 2009; Qin et al 2009; Yuzbas et al 2009; Salah and Ahmed 2012; Seyed and Ebrahim 2012). Muhib et al International Journal of Food Contamination (2016) 3:16 proteins, peptides, carbohydrates and other molecules (Vegarud et al 2000). Most of these trace elements have beneficial health importance. Malhatet et al (2012) found that the contamination in milk is considered as one of the main dangerous aspects within the last few years

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Conclusion