SEMI-QUANTIFICATION OF MICROPLASTIC CONTAMINATION IN BEERS COMMERCIALIZED IN DISTRITO FEDERAL
Plastics; microplastics; beer; contamination; Distrito Federal; human health; environment.
Microplastics (MPs) are solid structures characterized as plastic particles smaller than five millimeters. Currently, the presence of MPs has been recorded in the most diverse ecosystems around the globe, in aquatic and terrestrial environments, regardless the distance between those sites and the regions that host human activities. They are also found in various types of food and in daily-life consumer goods. MPs pollution is not a recent concern, neither are the warnings about their potential negative impact on the environment and on human health. Studies on the presence of MPs in food and drinking water have been complemented by more recent ones that show that the contamination also extends to non-nutritional consumer goods. Since beer holds a prominent rank among the non-nutritional beverages consumed by Brazilian adults, this study was designed to evaluate the presence of MPs in 20 different brands of beer produced in Brazil and commercialized at Distrito Federal, using canned and glass-bottled samples of each of the studied brands. The samples were filtered using a metal mesh filter with diameter of 25 micrometer, and the residual liquid was separated for qualitative and semi-quantitative analysis by manual counting in a Sedgewick Rafter chamber. Nile Red dye was used for recognition of MPs fragments by fluorescence microscopy. Simple percentage calculation was performed to determine the number of MPs particles in the different volumes of each sample. The results showed the presence of MPs in all canned beer samples and in only one glass-bottled beer sample. The average number of MPs found in the canned beer samples was 195 ± 136 per can, ranging from 12 to 508. Considering the average number of MPs per liter of beer, the canned samples averaged 587 ± 422 MPs particles per liter (MPs/L), ranging from 44 to 1,516. The only glass-bottled beer sample that showed microplastic contained 109 MPs/L. Further analyses showed a statistical difference (p < 0.001) between beer brands with respect to MPs concentration, with stratification of brands according to values significantly above and below the expected proportion (with 95% confidence interval). Regarding the geographic location where the brands were manufactured, it was observed that two cities hosted industries with the highest and with the lowest concentrations of MPs/L. The mean value of MPs/L found in this study was considerably higher than those described in previous studies. Although the methodologies used in the studies were different, which generates limitations in comparing results, the data obtained in this study represent the first study with this focus in Brazil, contributed with new data on this subject, corroborate the presence of MPs in beers in Brazilian territory and reinforce the alert to science, public health management areas, industries and to the population about the MPs contamination in beers manufactured and sold in Brazil.