Health Risk Assessment and Seasonal Trend of Metals in Arid-Soil-Forage Crops and Animals

Background: The aim of study was accessing the cobalt (Co) and lead (Pb) contamination in soil, forages and animals. The heavy metal ions bioaccumulation and escalating transfer to food chain has become main concern for mankind. Nevertheless, they play crucial role in organismal metabolism, however exceeding threshold level causes toxicity or even system failure. Since the plants are the main source of nutrition supply and carbohydrates for animal metabolism, therefore mankind exposure risk to food chain heavy metal toxicity increases significantly. Method: To highlight toxicity levels and exposure risk we designed this field study in the nearby areas of district Mianwali, Punjab, Pakistan during different seasons. and carried out samplings of soil, native flora. While following research ethics we collected samples of blood, hair and feces from domestic herbivore animals. Traditional wet digestion was carried out in available laboratory facilities, Pb and Co heavy metal concentrations were analyzed with atomic absorption spectrum. With emphasis on health risk index (HRI) and bio-concentration factor (BCF), we also draw attention to pollution load index (PLI), daily intake of metal (DIM), Health Risk Index (HRI) and Enrichment factor (EF). Results: : Our findings revealed high Pb concentration (5.29-9.84 mg/kg) in forage during season 1. While our findings indicate concentrations of metal in different seasons. When the Co concentration in forages was 0.238 to 0.492 mg/kg and Pb was found in the range of 5.29-9.84 mg/kg). Soil samples showed higher level of (PLI) Pollution load index. Bio-concentration of cobalt and lead was (0.447- 1.106 and 0.717- 1.152 mg/kg) respectively. Conclusions: : Bio-concentration factor and pollution load index for Co and Pb was noticed significantly higher than 1. Whereas enrichment factor (EF) was under permissible limit for both metals, daily intake metal (DIM) and no harmful health risk concentration was found. Therefore, wide-scale regular monitoring for heavy metal risk assessment on seasonal basis are highly recommended to avoid or minimize further contamination.