Evaluation of household plastic waste management in large brazilian cities

Solid waste generation is inherent in human activities, but inappropriate management can adversely affect human and environmental health. Plastic waste, in particular, has generated a particular concern, as studies have shown the adverse effects of the inadequate disposal of plastic waste on ecosystems. The general objective of this work is to evaluate the management of urban solid waste, with emphasis on domestic plastic waste in large Brazilian cities, Porto Alegre, Curitiba, Sao Paulo, Rio de Janeiro, Brasília, Fortaleza, Belém, and Manaus, especially in what It concerns the recovery of plastic from selective collection. To this end, information on the generation and waste collection of these eight municipalities was obtained from the National Sanitation Information System – SNIS, from 2016 to 2020. In order to evaluate the management of domestic plastic waste, the parameters used were related to the amount of waste collected by selective and conventional collection, as well as the total amount of recovered plastic. The data were obtained from the SNIS. The parameters related to the generation of plastic and the percentage of plastic recovered considering the total generated were estimated from SNIS and based on the Integrated Management of Solid Waste Plans developed by the municipalities assessed. Spearman correlation analysis was used to identify relationships between indicators related to the recovery of domestic plastic waste and socioeconomic aspects (Human Development Index and Gross Domestic Product). The results showed that among the evaluated municipalities, São Paulo and Rio de Janeiro are the largest generators of domestic plastic waste. In contrast, Belém and Porto Alegre are the smallest ones. The average amount of plastic generated did not vary in the studied period. In general, the results indicate low percentages of plastic waste recovery for all studied municipalities; the recovery percentage did not pass an average of 10%. Porto Alegre, Brasília, and Rio de Janeiro presented the largest percentages of plastic waste recovery (4.9%, 5.7%, and 3.4%, respectively), but Brasília presented a reduction tendency for the recovery of domestic plastic waste. There was also a positive correlation between plastic recovery and selective collection with the Gross Domestic Product of the municipalities (r = 0.7). While for some municipalities, such as Curitiba and Porto Alegre, the selective collection coverage rate reaches 100%, in other municipalities, it did not go beyond 5%, as in Belém and 19% in Manaus. These results are important because they provide us a reflection on the plastic waste management issue and draw attention to municipal solid waste management programs adopted in large Brazilian cities.