Assessment of municipal solid waste from households in Khulna city of Bangladesh

Sources and distribution of potentially toxic elements in urban road dust: A comparative insights and risk assessment of two polluted cities

This study provides a comprehensive comparative analysis of seven potentially toxic elements (PTEs) from thirty samples using instrumental neutron activation analysis on the roadside dust samples collected from a south-western city (Khulna) and a highly urban megacity (Dhaka), Bangladesh. The mean concentrations (μg.g-1) of Cr, Mn, Fe, Co, Zn, As, and Sb in the analyzed dust samples were 67.5±33.2, 386±136, 25648±5334, 6.86±1.79, 98±63, 3.02±1.08, and 1.37±1.10, respectively in Khulna city and 66.7±6.9, 547±110, 25150±1723, 8.39±0.65, 125±17, 3.63±0.56, and 0.75±0.28, respectively, in Dhaka city, showing uneven distribution in both cities. PMF modelling and multivariate statistical approaches demonstrated that 65.68% anthropogenic and 34.32% geogenic sources for Khulna city, whereas 64.93% mixed (anthropogenic and geogenic) and 35.07% anthropogenic sources were the main contributors of measured elements in Dhaka city. In both cities, anthropogenic contributions were primarily linked to traffic emissions and industrial activity. Various geo-environmental indicators, including element-specific (Igeo, EF, CF), site-specific (Cd, mCd, PLI, NIPI), and ecological indices (Eri, RI), were used to assess the contamination characteristics of PTEs and contamination levels in both cities were in the following decreasing order: Sb >Zn >Cr >Fe >As >Mn >Co, whereas individual ecological risks were in the following decreasing order: Sb(34.28) >As(6.28) >Co(1.98) >Cr(1.47) >Zn(1.46) >Mn(0.50) in Khulna, and Sb(18.64) >As(7.56) >Co(2.43) >Zn(1.86) >Cr(1.45) >Mn(0.71) in Dhaka. The study site demonstrated lower potential ecological risks, even though non-carcinogenic and carcinogenic risks from various exposure pathways appeared minimal. Notably, children in both urban cities exhibited heightened vulnerability compared to adults.

The quantity and composition of household food waste: Implications for policy

Studies on food waste in Southeast Asia are currently limited, with a notable absence of comparative analyses investigating the volume and composition of food waste in urban and rural areas through direct measurement. This study aimed to analyze the differences in the quantity, composition, and drivers of household food waste between urban and rural areas. Household food waste was assessed through waste compositional analysis for food and diaries for beverages. This cross-sectional study included 215 households in Bogor Regency, Indonesia. Comparisons between the two areas were performed using an independent t-test. The average of household food waste in Bogor Regency was 77 kg/cap/year (edible 37.7%, inedible 62.3%). Household food waste was higher in urban areas (79.4 kg/cap/year) than in rural areas (45.8 kg/cap/year) (p<0.001). Cereals, tubers and their derivatives (especially rice) and vegetables were the major contributors to edible food waste, whereas fruits were the main contributors to inedible food waste in both areas. Food waste drivers were spoilage/staleness/moldiness, changes in texture, short shelf life, cooking too much, and plate leftovers. Households in urban areas had a higher quantity of food waste and disposed of more edible food than those in rural areas. Meanwhile, the drivers of food waste generation were similar in both areas. Understanding the quantity, composition, and drivers of household food waste is pivotal for developing effective awareness campaigns and fostering behavioral changes to prevent household food waste.

Forecasting municipal solid plastic waste generation and management policy using system dynamics: a case study of Khulna City in Bangladesh

A comprehensive analysis of municipal solid plastic waste (MSPW) management while emphasizing plastic pollution severity in coastal cities around the world is mandatory to alleviate the augmenting plastic waste footprint in nature. Thus, decision-makers' persuasion for numerous management solutions of MSPW flow-control can be met through meditative systematic strategies at the regional level. To forecast solutions focused on systematic policies, an agent-based system dynamics (ASD) model has been developed and simulated from 2023 to 2040 while considering significant knit parameters for MSPW management of Khulna City in Bangladesh. Baseline simulation results show that per-capita plastic waste generation will increase to 11.6 kg by 2040 from 8.92 kg in 2023. Eventually, the landfilled quantity of plastic waste has accumulated to 70,000 tons within 18 years. Moreover, the riverine discharge has increased to 834 tons in 2040 from a baseline quantity of 512 tons in 2023. So the plastic waste footprint index (PWFI) value rises to 24 by 2040. Furthermore, the absence of technological initiatives is responsible for the logarithmic rise of non-recyclable plastic waste to 1.35*1000=1350 tons. Finally, two consecutive policy scenarios with baseline factors such as controlled riverine discharge, increased collection and separation of plastic waste, expansion of recycle business, and locally achievable plastic conversion technologies have been simulated. Therefore, policy 2, with 69% conversion, 80% source separation, and 50% riverine discharge reduction of MSPW, has been found adequate from a sustainability perspective with the lowest PWFI ranges of 3.97 to 1.07 alongside a per-capita MSPW generation of 7.63 to 10 kg from 2023 till 2040.

In-depth analysis to develop a social marketing model to promote women's participation in waste segregation behaviour: A qualitative study

Waste separation is one of the key factors in managing solid waste and creating a healthy environment. Waste separation at source has always been associated with challenges. Therefore, this study was conducted to determine the perceptions of housewives and related parties regarding the factors that influence waste separation behaviour and to identify approaches to improve behaviour based on the social marketing framework. This study was conducted as a qualitative content analysis in Amol City in 2022. The data was collected through semi-structured individual interviews. A total of 25 housewives were selected as main participants and 5 stakeholders through purposive selection. The results of the study included lack of awareness of recyclable materials (product), personal, family and environmental barriers (price), lack of doorstep collection of dry waste (place), and lack of use of appropriate technology (promotion). The lack of financial resources, inappropriate political measures and the coronavirus pandemic were also the causes of this challenge. Most participants cited environmental and educational deficits as the main reason for not separating waste. It is possible to improve waste sorting behaviour at source through appropriate behavioural interventions at the individual, social and environmental levels. Researchers can use the results of this study to design, implement and evaluate waste segregation intervention programmes for housewives.