Microplastic contamination in processed and unprocessed sea salts from a developing country and potential risk assessment.
In aquatic environments, microplastics (MPs) are pervasive which could have a considerable negative impact on the environment, organisms and pose a risk to human health. However, knowledge about the exposure and ecological risk of MPs in the coastal ecosystems of developing countries is limited. In this study, we analyzed salt samples from five commonly consumed processed and unprocessed sea salts of different commercial brands originated from 15 salt pans in Bangladesh to assess the abundance, characteristics and potential risks of MPs. The quantities of MPs in unprocessed salts (average 195 ± 56 item/kg) were higher than those in the processed salts (average 157 ± 34 item/kg). One-way analysis of variance (ANOVA) showed significant (p < 0.05) differences among the average numbers of MPs in both processed and unprocessed salts. MP levels in this study were 2-3 times higher than those reported from some other countries. Fiber-shaped and transparent MPs were dominant in both cases. MPs less than 0.5 mm in size were the most abundant in both unprocessed (58.2%) and processed (62.2%) salts. Fourier-transform infrared spectroscopy (FTIR) analysis confirmed five types of polymers, including polyethylene terephthalate (PET-35%), polypropylene (PP-27.5%), polyethylene (PE-25%), polystyrene (PS-10%), and Nylon (2.5%) in the studied salts. The sea salts were classified as potential hazard index (PHI) levels IV to V, indicating serious MP contamination, whereas potential ecological risk factor (Ei), potential ecological risk index (RI), and pollutant load index (PLI) indicated moderate levels of pollution of MPs. Domestic and municipal wastewater effluents to Bay of Bengal and fishing activities may attributed to presence of MPs in the sea salt. These findings can be used by consumers, salt industries and policy makers to reduce MPs levels during consumption, production and policymaking.
Ujjaman Nur AA
,Hossain MB
,Banik P
,Choudhury TR
,Liba SI
,Umamaheswari S
,Albeshr MF
,Senapathi V
,Arai T
,Yu J
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Microplastic contamination and risk assessment in table salts: Turkey.
In this study, the characterization of microplastics of table salts (n = 36) was determined by FT - IR. Then, individuals' exposure to microplastics from table salt consumption was calculated with a deterministic model, and finally, a risk assessment of table salt was performed using the polymer risk index. On average, 44 ± 26, 38 ± 40, 28 ± 9, and 39 ± 30 microplastics/kg were detected in rock salts (n = 16), lake salts (n = 12), sea salts (n = 8), and all salts (n = 36). Microplastics with 10 different polymer types (CPE, VC-ANc, HDPE, PET, Nylon-6, PVAc, EVA, PP, PS, Polyester), 7 different colors (black, red, colorless, blue, green, brown, white, gray), and 3 different shapes (fiber, granulated, film) were found in table salts. The daily, annual and lifetime (70-year) exposures to microplastics from table salt consumption in 15+-year-old individuals (general) were calculated to be 0.41 microplastic particles/day, 150 microplastic particles/year and 10,424 microplastic particles/70-year, respectively. The average microplastic polymer risk index of all table salts was calculated as 182 ± 144 and the risk level is in the medium. In order to minimize microplastic contamination in table salts, protective measures should be taken at the source of the salt, and production processes should be improved.
Özçifçi Z
,Basaran B
,Akçay HT
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Consuming microplastics? Investigation of commercial salts as a source of microplastics (MPs) in diet.
The omnipresence of microplastics (MPs) in marine and terrestrial environments as a pollutant of concern is well established and widely discussed in the literature. However, studies on MP contamination in commercial food sources like salts from the terrestrial environment are scarce. Thus, this is the first study to investigate various varieties of Australian commercial salts (both terrestrial and marine salts) as a source of MPs in the human diet, and the first to detect MPs in black salt. Using Nile red dye, the MPs were detected and counted under light microscopy, further characterised using attenuated total reflectance Fourier transformed infrared spectroscopy (ATR-FTIR) and scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM-EDS). Of all the 90 suspected particles, 78.8% were identified as MPs with a size ranging between 23.2 µm and 3.9 mm. The fibres and fragments constituted 75.78% and 24.22% respectively. Among the tested samples, Himalayan pink salt (coarse) from terrestrial sources was found to have the highest MP load, i.e. 174.04 ± 25.05 (SD) particle/kg, followed by black salt at 157.41 ± 23.13 particle/kg. The average concentration of detected MPs in Australian commercial salts is 85.19 ± 63.04 (SD) per kg. Polyamide (33.8%) and polyurethane (30.98%) were the dominant MP types. Considering the maximum recommended (World Health Organization) salt uptake by adults daily at 5 g, we interpret that an average person living in Australia may be ingesting approximately 155.47 MPs/year from salt uptake. Overall, MP contamination was higher in terrestrial salts (such as black and Himalayan salt) than the marine salt. In conclusion, we highlight those commercial salts used in our daily lives serve as sources of MPs in the diet, with unknown effects on human health.
Kuttykattil A
,Raju S
,Vanka KS
,Bhagwat G
,Carbery M
,Vincent SGT
,Raja S
,Palanisami T
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