Microplastics pollution in salt pans from the Maheshkhali Channel, Bangladesh

Abstract

Microplastics (MP) were recognized as an emergent pollution problem due to their ubiquitous nature and bioaccumulative potential. Those present in salt for consumption could represent a human exposure route through dietary uptake. The current study, conducted in Bangladesh, reports microplastics contamination in coarse salt prepared for human consumption. Sea salt samples were collected from eight representative salt pans located in the country's largest salt farming area, in the Maheshkhali Channel, along the Bay of Bengal. Microplastics were detected in all samples, with mean concentrations ranging from 78 ± 9.33 to 137 ± 21.70 particles kg−1, mostly white and ranging in size from 500–1000 µm. The prevalent types were: fragments (48%) > films (22%) > fibers (15%) > granules and lines (both 9%). Fourier transform mid-IR and near-IR spectra (FT-MIR-NIR) analysis registered terephthalate (48%), polypropylene (20%), polyethylene (17%), and polystyrene (15%) in all samples. These results contribute to the MP's pollution knowledge in sea salts to understand and reduce this significant human exposure route and environmental pollution source in the future.

Spatial distribution and risk assessments due to the microplastics pollution in sediments of Karnaphuli River Estuary, Bangladesh

“…MPs contamination factor (CF), pollution load index (PLI), pollution risk index (PRI), and polymeric risk assessment (H) in the river sediment were estimated as described in previous studies 24 , 43 , 44 . Tomlinson et al 45 proposed the contamination factors (CF) and pollution load index (PLI) to assess the pollution level in natural ecosystems.…”

“…Tomlinson et al 45 proposed the contamination factors (CF) and pollution load index (PLI) to assess the pollution level in natural ecosystems. CF, PLI, PRI, and H were categorized as values from low contamination to very high contamination, described in Table 1 24 , 43 , 44 .…”

“…Equations ( 3 ) and ( 4 ) presented polymeric risk assessment for different sampling sites and the entire Karnaphuli River Estuary, Bangladesh, respectively. P ji denotes the number of and S j presents risk score for each single MPs polymer recognized at ith station 24 , 47 , whereas H river is calculated as the nth root of the polymer risk indices products (Eq. 4 ), as follows: …”

“…Despite this, only a few studies have been conducted on the status and risk assessment of MPs pollution in Bangladesh. High abundance of MPs was determined in the sediments of Cox’s Bazar 1 , 2 , 23 , in salt pans from Moheskhali channel 24 , in tiger shrimp, brown shrimp, Bombay-duck, and gold-stripe sardine from the northern Bay of Bengal 25 , 26 . As rivers and estuaries are the main sources of land-based MPs flowing into the ocean, investigating the abundance, distribution, and potential risks of MPs in estuarine, marine, and coastal ecosystems is necessary for adequately maintaining the estuary ecosystems and human health.…”

Preliminary observation of microplastic contamination in some spice-salt samples purchased in Hanoi city

“…Dạng sợi vi nhựa chiếm chủ yếu trong các mẫu muối cũng đã được ghi nhận trong một số nghiên cứu trước đây. Ví dụ, dạng sợi vi nhựa được tìm thấy chủ yếu trong muối biển ở kênh Maheshkhali, dọc theo Vịnh Bengal [13] và các vùng làm muối ở một số tỉnh Thái Bình, Thanh Hóa, Quảng Bình, Quảng Ngãi, Bình Đình, Ninh Thuận, Bà Rịa Vũng Tàu, Bến Tre và Bạc Liêu: dạng sợi chiếm 83% và dạng mảnh chiếm 17% [5]. Giảm thiểu ô nhiễm vi nhựa trong môi trường, đặc biệt là vùng ven biển sản xuất muối là điều cần thiết.…”