Ecological risk assessment of heavy metal chromium in a contaminated pastureland area in the Central Punjab, Pakistan: soils vs plants vs ruminants.

Grazing animals act as a bioindicator to study the heavy metal status in the pasture lands because excessive amount of toxic metals in the animal diet either disturb their normal activity or deposit the contaminants into their tissues. The aim of this study was to appraise the chromium status in soil and pasture crops with respect to the nutritional requirement of grazing animals. Three different sites were selected to collect soil, forages, and animal samples from District Jhang. All the samples were processed through atomic absorption spectrophotometer to analyze the chromium concentration in them. Chromium concentration was varied as 0.703-4.20 mg/kg in soil, 0.45-2.85 mg/kg in forages, and 0.588-2.37 mg/kg in all collected animal samples. Both the soil and forage samples displayed the maximum chromium concentration in the Capparis decidua, whereas animal samples revealed maximum concentration in animal blood. Results of pollution load index (0.078 to 0.463 mg/kg) exhibited that all the sample values are less than unity while enrichment factor (1.57-8.25mg/kg) showed that significant level of chromium is enriched in these sites. The maximum value of daily intake (0.0007-0.0055mg/kg/day) and health risk index (0.0004-0.00370055mg/kg/day) was observed in the buffalo that feed on the Capparis decidua. Bio-concentration factor (0.398-2.09mg/kg) value was the maximum in the Medicago sativa. It is concluded that all the animal samples showed chromium concentration beyond their standards. Thus, proper measures should be taken to reduce the metal contamination in these areas that ultimately lessen the availability of toxic metals to grazing animals.

Evaluation of potential ecological risk and prediction of zinc accumulation and its transfer in soil plants and ruminants: public health implications.

Present work evaluated the zinc (Zn) concentration in soil, forage, blood plasma, hair, and feces samples of cows, buffaloes, and sheep taken from Mianwali, Punjab, Pakistan. The concentration of Zn was found in the ranged of 21.82-35.09mg/kg, 32.59-42.17mg/kg, 0.927-2.48mg/l, 1.03-2.84mg/kg, and 0.923-1.98mg/kg in soil, forage, blood plasma, hair, and feces samples, respectively. The Zn concentration in soil, forage, blood, hair, and feces was safer compared to standard limits. Statistical analysis described that values for BCF, PLI, EF, DIM, and HRI ranged 1.03-1.57mg/kg, 0.486-0.782mg/kg, 0.457-0.696mg/kg, 0.048-0.08mg/kg, and 0.160-0.272mg/kg, respectively. It can be concluded from the present work that Zn concentration was safe in soil, forages, and animal samples. BCF was noticed as greater than 1 while PLI, EF, DIM, and HRI were found less than 1, so regular heavy metal analysis was required to appraise the contamination level in environment.

Evaluation of pasture allowance of manganese for ruminants.

The aim of this study was to access the Mn contamination in soil, forages, and animals. Heavy metal pollution is a matter of prime significance in natural environment. Through food chain, toxicity of heavy metals and their bioaccumulation potential are transferred into humans. Higher concentrations of metallic compounds are toxic to living organisms but these are essential to maintain body metabolism. Intake of food crops polluted with heavy metals is chief food chain channel for human exposure. Animals are exposed to heavy metal stress by the intake of richly contaminated food crops; those are chief part of food chain. Samples of soil, plant, animal blood, hair, and feces were collected to find contamination through wet digestion process in lab and metal analysis. Different forages were collected to study Mn content that was our major concern in this study. The present findings also emphasized on the assessment of bio-concentration factor (BCF). Other significant indices of mobility and pollution of metal were also calculated, i.e. pollution load index (PLI), daily intake of metal (DIM), health risk index (HRI), and enrichment factor (EF). The experimentation result showed different concentrations of metal in different seasons. The Mn concentration in forages was 20.01-28.29 mg/kg and in soil was 5.27-8.90 mg/kg. Soil samples showed higher level of (PLI) Pollution load index. Bio-concentration of MN was 2.59-4.21 mg/kg. It can be concluded that regular monitoring of the metal is essential to evaluate the contamination status. Mn contents were in the safe limits in soil and plants; however, its toxic level was observed in animals.