EFFECT OF BISPHENOL-A ON THE GROWTH, DEVELOPMENT, AND SURVIVAL OF EARLY STAGES OF ANURANS; A SYSTEMATIC REVIEW

Abstract

Bisphenol – A is a popular industrial chemical used in the production of polycarbonate plastics and epoxy resins. Bisphenol – A is a xenoestrogen and type-I endocrine disruptor that interferes with natural hormone signaling pathways, leading to physiological and developmental adversities in living organisms. Owing to high industrial usage and poor plastic waste management practices, bisphenol – A has become a ubiquitous contaminant in urban aquatic ecosystems around the world. Aquatic larval stages of frogs and toads of Order Anura are vulnerable for aquatic pollutants including bisphenol-A. However, research findings on the effects of bisphenol – A on Anurans are not comprehensive and inconclusive. Therefore, existing literature on growth-related effects of bisphenol – A on early life stages of Anurans were systematically reviewed. Literature search was carried out using keywords such as “bisphenol A”, “tadpoles”, “amphibians”, “xenoestrogens” across several data bases. Collected literature was screened according to inclusion and exclusion criteria of Preferred Reporting Items of Systematic Review and Meta-Analysisn (PRISMA) approach. Twelve articles were recruited for the systematic review. Systematic review revealed that survival rate of tadpoles decreases with increasing concentration of bisphenol – A under exposure concentrations of 110-10– 110-4 M. However, significant lower survival rates were observed only under non – environmentally relevant concentrations and prolonged exposures. Bisphenol – A induced morphological malformations such as oedema, flexures, short body length, and scoliosis were observed in concentrations higher than 210-5 M. Female – biased sex ratios were observed even under low concentrations such as 110-8 M and 1*10-7 M of bisphenol - A. According to the systematic review, bisphenol - A significantly affects Anuran larvae at non – environmentally concentrations leading to morphological abnormalities and increased morphology. However, female – biased sex ratios were evident even under low concentrations.