Assessment of heavy metal pollution in Brassica plants and their impact on animal health in Punjab, Pakistan

Growing Brassica rapa L. (Brassica rapa subsp. campestris (Linn.) Clapham) with wastewater and their use as a fodder for animals is a common practice in suburb of all cities in Punjab, Pakistan, despite the wastewater containing heavy metals is of public health concern. This study assessed the risk of heavy metals on animal health via consumption of B. rapa as fodder grown with wastewater, tube-well and canal water, and its source apportionment, in suburb of Multan City, Pakistan. Samples of B. rapa (n = 30) were collected from six agricultural farms and analyzed for cadmium (Cd), chromium (Cr), copper (Cu), manganese (Mn), nickel (Ni), and lead (Pb) by inductively coupled plasma-optical emission spectrometry (ICP-OES). Total target health quotient (TTHQ) values ranged 47.22 to 136.64 in wastewater irrigation farm, 2.32 to 3.71 in canal water, and 4.86 to 7.50 in tube-well water irrigation farms, respectively exhibiting high carcinogenic health risk to animals across the farms. B. rapa grown with industrial effluents exhibited the highest carcinogenic health risk, while the canal water posed the lowest risk. Multivariate statistical analyses indicated that the wastewater samples containing heavy metals and contaminated soils were common sources of B. rapa contamination. Proper treatment of wastewater for removal of toxic elements before application in agricultural fields may safeguard the health of animals, public, and the ecosystem.