Accumulation of As and Pb in Vegetables Grown in Agricultural Soils Contaminated by Historical Mining in Zacatecas, Mexico

Abstract

Historical mining activities are a source of environmental pollution that affects the food chain and the health of human beings. The aim of this study was assessment the accumulation of arsenic and lead in vegetables grown in agricultural soils contaminated by old mining in Zacatecas, Mexico. The concentration of arsenic and lead in agricultural soil and edible parts of carrot, garlic, and pepper was analyzed by atomic absorption spectrometry. The soil-vegetable bioconcentration factor and pollution load index were determined. The pH values of the farmland were alkaline. The concentration of arsenic in agricultural soil exceeds the permissible limit for arsenic of Mexican standards and international representing health risks. The lead content in most soil samples they were low. The arsenic and lead content in edible parts of species vegetable exceeded the national standard from various countries and the values established by the Codex Alimentarius (FAO-WHO). The highest arsenic concentration was found both in Capsicum annum and Allium sativum. The highest concentration of Pb was in pepper fruits. Among vegetable the high BCF value was for arsenic, ranging from 2.33 to 0.64, and the average for all vegetable samples was 1.01. The pollution index indicates that arsenic is the dominant pollutant accumulated in soil and vegetables grown in agricultural soils. According to the findings, the state and national agricultural and health authorities should not recommend the cultivation of vegetables in agricultural soil located in this area of historical mining activities. Likewise, preventive measures must be taken on the consumption of contaminated vegetables and certifying their safety.

Lead (Pb) Pollution in Soil: A Systematic Review and Meta-Analysis of Contamination Grade and Health Risk in Mexico

“…High Pb concentration in soil suggests an increase in the metal mobility and a higher probability of bioaccumulation. Muñoz et al (2021) identified, in Vetagrande (ZAC), vegetables with Pb concentrations greater than the limits (0.1 mg Pb/kg) established by the Food and Agriculture Organization of the United Nations (FAO); the vegetables analyzed by Muñoz were garlic (Allium sativum, 3.0 mg Pb/kg), carrot (Daucus carota, 5.0 mg Pb/kg), and bell pepper (Capsicum annuum, 9.6 mg Pb/kg) [81]. The health risk was determined by the non-carcinogenic and carcinogenic risks.…”