As the demand for fish increases, the amount of wastewater generated from fishponds is also increasing with potential environmental and public health effects from their indiscriminate disposal. This study aimed at comparative analyses of the physicochemical and heavy metal constituents and potential DNA damage by wastewaters from natural and artificial fishponds using Allium cepa assay. A. cepa were grown on 3.13, 6.25, 12.5, 25.0, and 50.0% (v/v; wastewater/tap water) concentrations of each wastewater. At 48 and 72 h, respectively, genotoxic and root growth inhibition analyses were carried out on the exposed onions. The onion root tips exposed to wastewaters showed a significant (P < 0.05) inhibition of root growth and cell division in a concentration-dependent manner. Additionally, chromosomal abnormalities like spindle disturbances, sticky chromosomes, micronucleus, bridges, and binucleated cells were observed in the exposed onions and their induction was higher significantly relative to the negative control. Generally, wastewater from the natural fishpond caused higher chromosomal aberrations than the wastewater from artificial fishpond. It is our belief that the cytotoxicity and genotoxicity observed in the onions were primarily caused by heavy metals like Cr, Cd, Fe, Pb, Cu, and Zn found in the wastewaters. These metals also showed a significant carcinogenic and non-carcinogenic risks in children and adults with Cd as the highest contributor to these detrimental risks. Ingestion route was the major exposure route to the toxic metals in these wastewaters. Wastewater from the natural fishpond showed a higher health risk than the wastewater from the artificial fishpond. These findings suggest that the wastewaters from natural and artificial fishpond contain compounds that might induce cytogenotoxicity in exposed organisms.

Heavy metals (HMs) are natural components of the Earth's crust that might originate from natural and anthropogenic sources. In excess quantities, the presence of these metals is harmful for both environment and human health. Taking this into account, various investigators examined bioaccumulator species in order to reduce environmental toxicity, among these Baccharis trimera. Therefore, the present study aimed to determine the capacity of B. trimera to bioaccumulate HMs and assess consequent cytogenotoxicity following exposure. B. trimera vegetative parts were collected from two groups (1) control, in which plants were cultivated in soil exposed to distilled water, and (2) exposed, in which plants were cultivated in soil exposed to HMs including manganese (Mn), iron (Fe), lead (Pb), copper (Cu), cobalt (Co), zinc (Zn), and chromium (Cr). HMs were quantified in cultivation soil and extracts (aqueous and ethanolic) as well as infusion of B. trimera vegetative parts. Root lengths and cytogenotoxic effects were determined using Allium cepa test. Results demonstrated that all HMs studied were absorbed and bioaccumulated by B. trimera. Root lengths were decreased when exposed to ethanolic extract of B. trimera cultivated in soil exposed to HMs solution, which was the extract that exhibited the highest cytogenotoxicity values. Thus, data demonstrated that B. trimera might serve as a bioaccumulator for the reduction of environmental toxicity associated with the presence of certain HMs.