Risk assessment of heavy metals in milk from cows reared around industrial areas in India.

This study assessed the health risk associated with exposure to heavy metals through consumption of milk from cows reared around industrial areas in India. Heavy metals, namely Cu, Zn, Cr, Pb, and Cd, were determined in water and forage from four locations as well as in milk produced by dairy cattle raised in these locations, using inductively coupled plasma-mass spectrometry. A quantitative risk assessment using probabilistic approaches was performed to assess the exposure of adults and children to the heavy metals via milk consumption. In milk samples, the highest levels of Cd and Pb were 0.18 mg L-1 and 0.37 mg L-1, respectively, which were above the international permissible levels. Possible sources of Pb in the milk could be the industrial by-products and wastes or automobiles exhaust gas. Significant (P < 0.05) positive relationships were found between the concentration of Cu, Cr, Pb, and Cd in milk and in the environmental samples (water or forage). Exposure assessment showed that milk consumers were mostly exposed to Zn, Cd, and Pb, with 63.7%, 51.2%, and 41.2% of children exposed to a dose greater than the references dose for these metals, respectively. Our results suggest that industrial activities lead to possible transfer of heavy metals to cows from their rearing environment (water, plant), which can be accumulated and cause potential health risks to milk consumers. The outcome of this study can be used by policy makers to manage the potential health risk.

Identification of suitable housing system for dairy cattle in North East Zone of Tamil Nadu, India, with respect to microclimate.

AIM: To identify the suitable roofing pattern for dairy cattle in North East Zone of Tamil Nadu, India, based on micro climatic conditions. MATERIALS AND METHODS: Initially, survey was conducted to identify and categorize the major housing patterns existing in the region for further detailed investigation. In total, 30 farmers/farms consisting of five housing types with six replicates were selected. Temperature and temperature humidity index (THI) were recorded using the maximum-minimum thermometer and digital thermo-hygrometers. The study was conducted for 1 year covering four seasons namely South West monsoon (June-August), North East monsoon (September-November), cold season (December-February), and summer season (April-May). The data were statistically analyzed using statistical package SPSS 17. RESULTS: Animal shelters with cement sheets recorded the highest temperature (26.71±1.13°C) and THI (77.23±1.76) at 8.00 am, whereas the lowest temperature (24.83±1.17°C) and THI (74.54±1.72) were recorded in the thatched shed. There was significant difference (p<0.01) in temperature and THI at 8.00 am during South West monsoon and North East monsoon seasons between the housing types. During cold and summer seasons, there was no significant difference (p≥0.05) in the environmental variables among various shelter systems. CONCLUSION: Thatched housing is found to be the suitable one with respect to the climatic variables, followed by tile roof and metal roof. The cement sheet roofed housing is found to be the most unsuitable one in the region for dairy cattle.