Transfer of lead from soil to pasture grass and milk near a metallurgical complex in the Peruvian Andes

Abstract

Milk quality is affected by the concentration of lead (Pb) in soil and pasture grasses used to raise cattle, especially in areas near mining-metallurgical complexes. In this study, the Pb content of soil and its transfer to grass and dairy milk in an area located to 20 km from the La Oroya Metallurgical Complex in Peru (altitude, >3700 m s.a.l) was measured. Twenty soil samples (0–30 cm depth), 20 grass samples were collected, and 0.5 L of milk was obtained from 20 lactating cow in the communal cowshed. The Pb concentration (mg/kg) was quantified by flame atomic absorption spectrometry using a commercial Pb standard as quality control. The Pb average concentration in the soil, grass, and milk samples were 217.81 ± 39.48, 20.09 ± 2.83, and 0.58 ± 0.018 mg/kg (p < 0.01), respectively. The transfer factor (ratio of metal concentration) for Pb from soil to grass and from grass to milk was 0.095 and 0.031, respectively. The soil, grass, and milk samples all presented high Pb concentrations, with the milk samples containing 29-fold more Pb than the safety limit established by European regulations and were not suitable for human consumption or the manufacture of cheese, yogurt, and other derivatives. Our findings demonstrate that action to remediate these soils is critically needed.

Assessing the Health Risk and Trophic Transfer of Lead and Cadmium in Dairy Farming Systems in the Mantaro Catchment, Central Andes of Peru

“…As such, the production of milk is safe for human consumption, if adequate control is guaranteed and trace metal remediation strategies are applied in the region [105]. Trace metals have accumulated for extended periods in soils in the valley from both the mining-metallurgy industries and the agricultural application of fertilizer [9,18,85]. This has also been reported in related studies elsewhere [40,85].…”

“…Trace metals have accumulated for extended periods in soils in the valley from both the mining-metallurgy industries and the agricultural application of fertilizer [9,18,85]. This has also been reported in related studies elsewhere [40,85]. At the same time, control of the use of phosphorus agrochemicals must be enforced in agriculture [40], since these agrochemicals are the principal source of Cd [88,106].…”

“…The world literature indicates that the content of heavy metals responds to the environmental conditions of each region and country [7,10,40,[80][81][82][83][84], and on a global scale, Peru is located at the top [42]. The main source of Pb contamination would be from irrigation water from the Mantaro River and fine particle emissions from the mining-metallurgy industry, descending onto pastures from atmospheric loading derived from mining activity and ore processing [85]. Regarding Cd, it was observed that the principal source of pollution comes from phosphorus-based fertilizers, commonly used in agricultural systems in the Peruvian central highlands [40].…”

Lead, Cadmium, and Arsenic in Raw Cow’s Milk in a Central Andean Area and Risks for the Peruvian Populations

“…The population in the central Andes of Peru has been exposed to emissions from mining-metallurgical activity for more than 100 years, whose vapors and dust travel in the air and are deposited in water and soil. Likewise, the high traffic on its roads and the misuse of fertilizers and agrochemicals based on phosphate rock in agriculture release heavy metals [23], a context that is also observed in many developing countries. Therefore, the products obtained from these soils must be monitored for their metal and metalloids content by evaluating the potential risk for their consumption, comparing them with toxicologically acceptable levels [4].…”

Lead, Cadmium, and Arsenic in Raw Milk Produced in the Vicinity of a Mini Mineral Concentrator in the Central Andes and Health Risk

“…The Mantaro Valley, located in the Central Andes of Peru, is exposed to contamination not only from emissions from the metallurgical complex of La Oroya, whose vapors and dusts travel in the air for many kilometers, but also from traffic, cement industries, and misuse of phosphorus products in agriculture and contaminate water and soil [ 16 ], a context observed in many developing countries. Therefore, products obtained from contaminated soils should be analyzed for the contents of heavy metals and other highly toxic substances and the risk of their consumption for humans.…”