Читать книгу Plastic and Microplastic in the Environment - Группа авторов - Страница 42

The plastic consumption rate among the Indian population is among the highest in the world, and results in the generation of approximately 5.6 million tons of plastic waste per year (Toxics Link 2014). Not surprisingly, India is described as the twelfth largest contributor of marine plastic pollution in the world (Jambeck et al. 2015), but very few studies to date have investigated the presence of MPs in the water or sediment in freshwater or estuarine environments in India. Recently there have been a few studies on MPs pollution in India but most of these studies are on coastal or marine sediments (Jayasiri et al. 2013; Reddy et al. 2006; Robin et al. 2020; Suman et al. 2020) and studies on fresh water environments are almost non‐existent (Table 2.1). Owens & Kamil (2020) carried out a study of plastic pollution in a river in Kerela, India (Karamana River) and Indonesia (Tukad Badung River).

In one of the first reports on MPs in the freshwater environments in India, Sruthy & Ramasamy (2017) studied the sediments of Vembanad Lake, a Ramsar site in India with low‐density polythene dominating the sediment samples. The authors pointed out that as the locals consume the aquatic fishes and clams from this lake, the fate of MPs entering humans via the food web is a potential threat. Ram & Kumar (2020) studied MPs from Sabarmati River sediments, where they reported that higher amount of MPs were observed in the river in areas near landfill sites from where the surface runoff might have carried the plastic debris to the river. Sarkar et al. (2019) estimated distribution of meso‐ and microplastics in the sediments of the lower reaches of the river Ganga, where they observed a relation between MPs abundance and other water quality parameters such as BOD. Karthik et al. (2018) studied MPs particles at beaches along the southeast coastal region of India, where they found the highest abundance of MPs on beaches adjacent to the river mouth. They also found the MPs in 10.1% of the 79 fishes they studied. Reddy et al. (2006) reported the observed plastic debris in the marine sediments on the coast of Gujarat, and a group of researchers reported plastic particles in the beaches of Mumbai (Jayasiri et al. 2013). Veerasingam et al. (2016) studied the MPs in surface sediments along the Chennai coast during March 2015 (pre‐Chennai flood) and November 2015 (post‐Chennai flood) and found that the MPs in the sediments increased threefold in post flooding, which may be due to huge input of MPs through the Cooum and Adyar rivers during the flood. This study highlights the importance of rivers as sources of plastic pollution to the marine environment.

Table 2.1 Concentrations and sizes of microplastics reported in samples from freshwater environments (studies from India).

Sl. No.	Location	Average concentration	Method	Sample type	Size	Polymer type	References
1	River Ganga	11.48–63.79 ng/g	FT‐IR	Sediments	63–850 μm, 850 μm–5 mm	PET, PE	Sarkar et al. (2019)
2	Sabarmati River	134.53–581.70 mg/kg	SEM	Sediments	4 mm–75 μm	Plastic debris and fibers	Ram & Kumar (2020)
3	Vembanad Lake	0.27 g/l	Raman	Sediments	0.2–1 mm	*HDPE, LDPE, PP, PS	Sruthy & Ramasamy (2017)
4.	Netravathi River	288 pieces/m3 (water), 96 pieces/kg (sediment) 84.45 pieces /kg (soil)	–	Water, sediments, and soil	5–0.3 mm	PE, PET	Amrutha & Warrier (2020)

^* Low‐density polyethylene (LDPE) High‐density polyethylene (HDPE).

In India, plastic litter is documented to have caused serious damage to biodiversity in places like Cochin, Lakshadweep, Sutrapada, Vembanad Lake, Chilika Lake, Mandapam, Kilakkarai, Erwadi and Periyapattinam. There are multiple cases of ingestion and entanglement from plastic debris leading to mortality of marine mammals and birds in the country. The tourism and fishing industries are significant contributors of plastic pollution in India, especially in the coastal areas, as these areas are being affected by plastic pollution. Recently, eight beaches in India have been recommended for the coveted “Blue Flag” international eco‐label, and we should be able to reduce plastic pollution to maintain the clean status of all our tourist places.^†

^† The ‘Blue Flag’ is a certification that can be obtained by a beach, marina, or sustainable boating tourism operator, and serves as an eco‐label. The certification is awarded by the Denmark‐based non‐profit Foundation for Environmental Education, which sets stringent environmental, educational, safety‐related, and access‐related criteria that applicants must meet and maintain. It is awarded annually to beaches and marinas in FEE member countries.

Amrutha & Warrier (2020) presented a detailed source‐to‐sink characterization of freshwater MPs collected from the water, sediment, and soil samples of the Netravathi River catchment, a tropical Indian river. The authors reported that sampling sites close to important religious places were observed to have higher concentration of MPs fibers, which may be due to garments washing.