Bovine milk chain in Italian farms. I. Arsenic levels in soil, gravitational and clean water, bovine diet, and milk.

摘要

Soil, crop, beverage and irrigated water samples were analysed for arsenic levels, as well as milk from lactating dairy cows from Italian dairy farms belonging to two territorial levels (national, 60 farms and regional, 10 farms) between 2003 and 2004. Results showed that at the national level, As level in water was lower than the fixed law limit for drinking water (10 micro g/litre). In milk samples, the level was lower than the normal concentration range of 20-60 micro g/litre. Only a small portion of feeds contained As, with levels lower than the allowable level of 2 mg/kg. At the regional level, 75% of the drinking water samples contained high levels of As at 85.10 micro g/litre. As concentrations in feed and milk were similar with the results obtained at the national level. As concentration in soil ranged from 6.6 to 31.1 mg/kg, which was within the normal range for uncontaminated agricultural soil. Because of the high amounts of water ingested during lactation, the average As intake of cows ranged from 11.17 to 11.43 mg/day (national level) and 14.37 mg/day (regional level). The cow's biotransfer factor (BTF) for arsenic in milk, due to exposure to food and water, was up to 5.55x10-4 in Cuneo province and 3.68x10-4 at the regional level.