Arsenic Pathways in the Environment: The Role of Contaminated Groundwater in the Dispersion of Arsenic to Soil, Vegetables and Chicken Meat

This study evaluated the dispersion of arsenic (As) in the environment due to the use of contaminated groundwater for the irrigation of vegetables and chicken watering in two small farms located in a rural and urban zone in southeastern Brazil. ICP-AES was used to perform As determinations in groundwater, soil and vegetables samples while ICP-OES was used for chicken meat and offal. The As concentrations in the groundwater of the urban and rural farms were above the limit allowed (0.01 mg L−1) by Brazilian regulations (0.040 ± 0.019 and 0.017 ± 0.007 mg L−1, respectively), while the concentrations found in the soil for the same locations were below the limit allowed (15 mg kg−1) (1.071 ± 0.538 and 1.366 ± 0.141 mg kg−1, respectively). Vegetable samples were within the legal limits (0.3, 0.2 and 0.1 mg kg−1 for roots, leaves and fruits, respectively), with the exception of beet fruit (0.114 ± 0.031 mg kg−1) in the urban farm and cassava leaf (0.339 ± 0.374 mg kg−1) in the rural farm. As a general trend, roots accumulated more As compared to fruits and leaves, in that order. With the exception of chicken meat, liver and lung, all other offal analyzed (roe, gizzard, heart and skin) had As concentrations above 1.0 mg kg−1, the maximum allowed limit. The As concentration’ ratio between the evaluated environmental compartments indicated that (1) irrigation acts as a point source of As for the farms; (2) the soil acts as an As accumulator compartment and (3) the plant roots act as a barrier to prevent As translocation to its aerial part. Since the highest As concentrations were found in the least consumed chicken offal, we can conclude that this does not pose a risk to the community in the surrounding study area, but they were warned about our data and its implications to their health.