Preliminary investigations on the occurrence and risk assessment of microplastics in the Bhoj wetland: a Ramsar site in Bhopal, Central India

Indiscriminate use of plastic materials and their improper disposal have resulted in the accumulation of plastics in various ecosystems including wetlands. The Bhoj wetland, a notified Ramsar site in Bhopal, Central India, was chosen in this study for investigating the presence of microplastics. Since the Bhoj wetland comprises two surface water bodies, the upper lake and the lower lake, sampling was done in both to understand the extent of microplastic contamination. Approximately 2.4 items/L in the upper lake and 6.6 items/L in the lower lake were identified, which belonged to polyethylene, polypropylene, polyvinyl chloride, polyamide, and polyester chemical classes. The occurrence of these items was attributed to tourist activities, along with the discharge of treated effluent from sewage treatment plants located in the vicinity. To further elucidate the impact of these contaminants on wetlands, ecological and human health risks were calculated. The ecological risk was found to be 'very low' or 'low'. The human health risk was calculated, considering the carcinogenic and non-carcinogenic nature of the obtained microplastic items. These risks were found to be within the acceptable level of adverse risk. The study concludes that there is a need for effective plastic waste management to minimize further contamination of the Bhoj wetland.