Conclusions and Recommendations
Vegetables grown in areas contaminated by water from the Rı´mac River had high levels of As and Pb, although a reduction in As has been observed over the last two years due to improvements in the Ministry of Energy and Mines’ regulatory systems. Regulations now exist which involve obligatory programmes of environmental adequacy as well as environmental impact assessments (MINEM, 1993). Despite the high levels of Pb found in the river water, the content found in soils and crops does not pose a signiﬁcant health risk. However, signiﬁcant levels of As and Cd were found in soil, and these could be harmful. Investigation of the Cd and As levels in vegetables showed that there was more accumulation in foliage than in roots. The indigenous aromatic plant huacatay contains Cd and As concentrations that are above those permitted by Peruvian law. Contamination of irrigation water with pathogens was a more serious problem for vegetable production. FC were found to reach levels higher than permitted by Peruvian law: more than 97 per cent of water samples from irrigation canals contained ﬁve million MPN/ 100ml, which is beyond the maximum permitted limits for FC bacteria. Analysis of lettuce and radish samples showed 17 per cent and 31 per cent of the samples having bacterial loads that are above permitted limits. The practice of washing vegetables using water from the irrigation canals further contaminated these vegetables: 57 per cent of clean vegetables were contaminated during the rinsing process.