The Migration of Chemical Contaminants from Polyethylene Bags into Food During Cooking

Abstract

Cooking food in polyethylene bags has of late substituted banana leaves in Uganda. However, such a practice is risky as chemical contaminants may migrate from polyethylene bags into food during cooking causing health complications. Therefore, this study was done to identify and quantify the levels of chemical contaminants (heavy metals) in black and green polyethylene bags. Polyethylene bags were ashed and digested with acid and heavy metal concentrations determined using an AAS. Samples analyzed contained heavy metals with concentrations ranging between; 1125 -1725, 76 -112, 35 -52, 18 -31 ppm for Pb, Cd, Cr and Co respectively. Heavy metal migration studies into posho cooked in the black polyethylene bags was done at 65 o C (T 1 ), 80ºC (T 2 ) and 95 o C (T 3 ). The highest migrated heavy metal concentrations 120.60, 12.25, 9.45 and 15.42 ppm for Pb, Cd, Cr and Co respectively were obtained at T 3 at the surface of the posho cube (0.5cm) after 5 hours of heating. While the lowest values for Pb (10.60 ppm), Cd (1.26 ppm), Cr (0.20 ppm) and Co (1.55 ppm) were obtained at T 1 towards the centroid of the posho cube (1.5 cm) after 2 hours of heating. Pb migrated highest followed by Co, Cr and Cd. Though small quantities migrated, over a long period of time they may accumulate in the body and cause health complications to the victims. To make this research of substantial importance to the polyethylene bag user, the findings were disseminated through media to the general public.

Estimation of Some Trace Metals Contamination in Waste Newspapers

“…(Table 3). These metals may come from the same sources, according to Musoke et al, such as colorants and additives used in the creation of food contact paper [47]. In conclusion, this is a thorough investigation on the presence of a wide spectrum of trace metals in diverse newspaper samples.…”

Microplastics in food commodities

“…They also reported an increase in the water concentration of two aldehydes and antimony (Sb), though no increase in the cytotoxicity, genotoxicity or estrogenic activity of water extracts in in vitro bioassays. A temperature-dependent release of heavy metals was also detected in food cooked in polyethylene bags, with a total migration of 7 percent, 16 percent, 8 percent and 48 percent for lead (Pb), cadmium (Cd), chromium (Cr) and cobalt (Co) respectively, resulting in food concentrations of up to 121, 12, 9.5 and 15 ppm after 5 hours of exposure at 95 °C, especially on the surface of the food (Musoke et al, 2015). Hernandez et al (2019) also investigated the release of micro-sized particles from plastic teabags when these are immersed in water at 95 °C and estimated an overall exposure to approximately 11.6 and 3.1 billion micro-and nanoplastics per cup of tea, respectively.…”

Untitled

“…Indeed, in other parts of the world, especially in developing countries, the use and 634 presence of heavy metals in plastic packaging is either not regulated, or regulated insufficiently, or 635 regulations are not properly enforced. For example, PE bags in Uganda contain cadmium, chromium, 636 cobalt, and lead, found to contaminate food cooked in these bags (Musoke et al, 2015), while in 637…”