Abstract
As concentrations in muscle, liver, milk, and hair of dairy cattle raised in northern Mexico were measured to determine whether the levels exceed those permitted by Mexican regulations (NOM). Furthermore, the possible accumulation of As in samples was evaluated in muscle, liver, milk and hair using atomic absorption spectrophotometry and a two-way ANOVA for unbalanced data was performed. The optimal model was determined and Tukey contrasts for multiple comparisons of means. The As was found in the highest concentrations in hair (6.09-7.13 mg L-1). In general, the concentrations of muscle and liver samples were found to be lower than NOM for human consumption. In milk, samples from G2 exceeded the permitted values, while in G3, only one sample exceeded the limit. No differences were observed between age groups; however, notable variations were identified among the different tissues (p < .0001). The findings indicate that the levels of As in tissues samples exceed the standards for human consumption and emphasise the necessity to enhance general environmental monitoring (predominantly water quality) in contaminated areas where cattle are raised for production.