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A recent study conducted in Dhaka, Bangladesh, has revealed the widespread presence of microplastic particles in both bottled and loose soybean oil, with the latter exhibiting significantly higher contamination levels. Researchers from Jahangirnagar University and Bangladesh University of Professionals (BUP) analyzed soybean oil samples collected from the capital, finding an average of 53,922 microplastic particles per litre. Loose oil samples contained approximately 24% more particles than their bottled counterparts. These significant findings were subsequently published in the esteemed Journal of Food Composition and Analysis.
The research team identified six distinct types of plastic polymers within the samples: low-density polyethylene (LDPE), high-density polyethylene (HDPE), polypropylene (PP), polyethylene terephthalate (PETE), polyurethane (PU), and nylon. The study's authors issued a warning regarding the potential health risks associated with long-term dietary exposure to these minute plastic particles.
Further analysis of 60 one-litre soybean oil samples showed that loose soybean oil contained an average of 59,778 particles per litre, compared to 48,067 particles per litre in bottled oil. Bottled oil samples were sourced from Dhaka supermarkets, while loose oil was collected from Tejgaon, Uttara, and Dhaka Cantonment. Researchers observed the highest contamination level, 70,467 particles per litre, in a loose oil sample from Tejgaon. According to the study, this higher contamination in loose oil could be attributed to factors such as proximity to plastic and textile factories, airborne synthetic fibres, and the repeated use of plastic containers. Bottled oil, too, was noted to be susceptible to contamination during processing and packaging through contact with plastic pipes, seals, filters, and storage containers.
Fibres constituted the predominant form of microplastics, accounting for 82.5% of all detected particles, followed by fragments at 9.6%. Transparent particles were the most common visually, representing 56.29% of the total. The majority of particles measured between 101 and 500 micrometres, with another considerable portion falling within the 501 to 1,000 micrometre range. Utilizing Fourier Transform Infrared Spectroscopy (FTIR), the researchers confirmed the six plastic polymers, highlighting that this study marks the first reported detection of polyurethane and nylon in soybean oil in Bangladesh. These materials, the researchers posited, might have entered the oil via processing equipment, seals, filters, or packaging.
Professor Shafi M Tareq of Jahangirnagar University's Department of Environmental Sciences, a co-author of the study, stated, 'We analysed both branded and loose soybean oil sold in Dhaka and found thousands of microplastic particles per litre, with fibres and fragments being the most common.'
The study also attempted to quantify potential human exposure to these microplastics. Based on average soybean oil consumption and assumed body weights (70kg for adults, 16kg for children), it was estimated that adults could ingest approximately 17.65 microplastic particles daily, while children might consume 77.21 particles per day. Annually, this translates to an estimated 6,441 particles for adults and 28,180 for children. A child's lifetime exposure was projected to be around 2.09 million particles. The researchers emphasized that these figures are modelled estimates derived from consumption patterns and body weight, not direct measurements within the human body.
Referencing existing scientific literature, the researchers outlined potential health concerns linked to prolonged microplastic exposure, including gastrointestinal inflammation, hormonal disruption, metabolic disorders, and cellular damage. They also pointed out that particles smaller than 130 micrometres could potentially traverse the intestinal wall and enter body tissues, though their study did not directly investigate human health effects. Professor Tareq further elaborated, 'Microplastics are now considered an emerging contaminant. They may create long-term risks to human health, including hormonal imbalance, metabolic problems and adverse effects on the reproductive system.' While the study classified all six sample groups as having moderate contamination based on its microplastic contamination factor, the overall pollution-load index placed them in the low pollution-risk category, a comparative measure rather than an official food safety standard.
Dr. MH Choudhury Lelin, a public health expert, underscored the growing concern surrounding microplastics, noting their detection in various human organs and numerous everyday consumer products. He cautioned that harmful chemicals can adhere to microplastic particles, potentially escalating the risk of cancer and causing damage to vital organs such as the liver and kidneys.
The researchers underscored a critical gap in Bangladesh's regulatory framework, noting the absence of specific regulations and routine monitoring systems for microplastics in food. This deficiency, they argued, hinders a comprehensive understanding of contamination levels and potential health impacts. They put forth recommendations for stricter quality control across all stages of soybean oil production—refining, storage, transportation, and marketing—including the implementation of food-grade filters and enhanced oversight of loose oil sales. Professor Tareq acknowledged the practical difficulties, stating, 'Completely eliminating plastic is not realistic at present. Alongside proper plastic waste management, reuse and recycling systems must also be strengthened.' The study concluded by stressing the imperative of reducing contamination throughout the food production chain to bolster food safety and safeguard public health.
Source: Bangladesh Post