Current scenario and challenges of plastic pollution in Bangladesh: a focus on farmlands and terrestrial ecosystems

● A global snapshot of plastic waste generation and disposal is analysed. ● Effect of plastic pollution on environment and terrestrial ecosystem is reviewed. ● Ecotoxicity and food security from plastic pollution is discussed. Plastic is considered one of the most indispensable commodities in our daily life. At the end of life, the huge ever-growing pile of plastic waste (PW) causes serious concerns for our environment, including agricultural farmlands, groundwater quality, marine and land ecosystems, food toxicity and human health hazards. Lack of proper infrastructure, financial backup, and technological advancement turn this hazardous waste plastic management into a serious threat to developing countries, especially for Bangladesh. A comprehensive review of PW generation and its consequences on environment in both global and Bangladesh contexts is presented. The dispersion routes of PW from different sources in different forms (microplastic, macroplastic, nanoplastic) and its adverse effect on agriculture, marine life and terrestrial ecosystems are illustrated in this work. The key challenges to mitigate PW pollution and tackle down the climate change issue is discussed in this work. Moreover, way forward toward the design and implementation of proper PW management strategies are highlighted in this study.     

Evidential role of municipal solid waste and liquid effluent on environment and public health

Cities in Bangladesh produce large amounts of solid waste (SW) through various human activities which severely pollutes our native environment. As a result, SW pollutes the three basic environmental elements (air, water, and soil) by increasing pathogenic microbial load, which might be hazardous to public health directly or indirectly. In this study, we conducted 30 samples (i.e., soil, water, and air) collected from areas where municipal solid wastes are dumped (Tangail Sadar Upazila, Bangladesh). All the samples were analyzed to assess bacteriological quality for presumptive viable and coliform count using different agar media. We performed serial dilution 10⁻³–10⁻¹⁰ times for soil and water samples, and the diluted samples were spread on Mac-Conkey agar and nutrient agar plates. For the air sample, the sterile media containing petri-dish was placed adjacent to the dumpsite of the municipal waste and kept for an hour. Then all the samples were incubated at 37°C overnight for total viable count (TVC) and total coliform count (TCC). Biochemical tests and PCR were performed for the identification of these microorganisms. The antibiogram study was performed to reveal their (identified bacteria) susceptibility against clinically used antibiotics according to the standard disk diffusion technique. The highest bacterial loads were found in the air: TVC 3.273 × 10³ and TCC 1.059 × 10³ CFU/plate; tube-well water: TVC 8.609 × 10³, and TCC 8.317 × 10³ CFU/mL; in surface water: TVC 6.24 × 10¹³ CFU/mL and TCC 2.2 × 10¹² CFU/mL; in soil: TVC 2.88 × 10¹¹ and TCC 1.02 × 10¹¹ CFU/g, respectively. Microbes from SW can be transmitted through air, dust particles, or flies, and here we found an average of 1120 microbes spread over 63.61 cm² area per hour. Eight bacterial isolates (Pseudomonas spp., Klebsiella spp., E. coli, Proteus spp., V. cholera, Salmonella spp., Shigella spp., and Vibrio spp.) were identified by the biochemical test. Among them, E. coli and Shigella spp. were further ensured by PCR targeting bfpA and ipaH genes. Antibiotic susceptibility test results showed that E. coli isolates were highly resistant to erythromycin (80%); Shigella spp. were resistant to nalidixic acid (90%), whereas Salmonella spp. was found resistant to kanamycin (90%). Vibrio spp. were also resistant to azithromycin (80%) and erythromycin (80%), which should be a great concern for us. A semi-structured survey revealed that 63% of respondents suffered from different clinical conditions (intestinal diseases) due to SW pollution. So, steps should be taken to improve the proper management and disposal of solid waste and liquid effluent to save our environment and public health.     

Potential health hazard of drinking water in restaurants and tea stalls

Potable and equitable drinking water (DW) is a fundamental human right and essential for human health. This study is conducted to assess the groundwater and jar water quality of the roadside restaurants and tea stalls used for drinking by the local people around the Gazipur City area in Bangladesh. Water samples from 173 restaurants and tea stalls are collected. The physico-chemical and biological parameters are analyzed according to the guidelines and standards. The results illustrate that the color, EC, and Mn of 41%, 80%, and 62% of the samples, respectively, exceed the WHO and Environmental Conservation Rules (ECR) standards. In addition, E. coli and total coliform exceeding the threshold standards are found in 47% and 64% of the water samples, respectively. The contamination of DW by fecal coliforms is confirmed and supported by prior studies, which indicates that the DW supplied in restaurants and tea stalls are unsafe because of the possible presence of pathogens. These may cause potential health hazards to consumers from various water-borne diseases. Poor sanitation, unhygienic practices, and improper disposal of wastewater are responsible for the microbial contamination of DW. So, the authorities in charge of these places should take the right regulatory steps, such as regular sanitation inspections, DW quality monitoring, hand-washing practices, and better sanitation in these places.     

Variability and predictability of sea-level extremes in the Hawaiian and U.S.-Trust Islands—a knowledge base for coastal hazards management

The objective of this study is to provide an improved climatology of sea level extremes on seasonal and long-term time scales for Hawaii and the U.S-Trust islands. Observations revealed that the Hawaiian and U.S.-Trust islands, by and large, display a strong annual cycle. For estimating the statistics of return period, the three-parameter generalized extreme value (GEV) distribution is fitted using the method of L-moments. In the context of extremes (20- to 100-year return periods), the deviations in most of the Hawaiian Islands (except at Nawiliwili and Hilo) displayed a moderate sea-level rise (i.e., close to 200 mm), but the deviations in the U.S.-Trust islands displayed a considerably higher rise (i.e., more than 300 mm) in some seasons due to typhoon-related storm surges. This rise may cause damage to roads, harbors, and unstable sandy beaches. Correlations between the El Niño-Southern Oscillation (ENSO) climate cycle and the variability of seasonal sea level have been investigated. Results show that correlation for the station located west of the International Date Line (DL) is strong, but it is moderate or even weaker for stations east of the DL. The skill of SST-based Canonical Correlation Analyses (CCA) forecasts was found to be weak to moderate (0.4–0.6 for Honolulu, Kahului, Hilo, and Wake, and 0.3 or below for Kahului, Mokuoloe, and Johnston). Finally, these findings are synthesized for evaluating the potential implications of sea level variability in these islands.     

Appraisal of stormwater-induced runoff quality influenced by site-specific land use patterns in the south-eastern region of Bangladesh

Environmental Science and Pollution Research - Urban stormwater runoff is considered as one of the major contributors to nonpoint source that contributes to the pollution of all water resources in...     

The ameliorative effects of ceftriaxone and vitamin E against cisplatin-induced nephrotoxicity

Environmental Science and Pollution Research - Nephrotoxicity is a common adverse effect of treatment with cisplatin (CDDP). This study was performed to evaluate the antioxidant and...     

Health cost of salinity contamination in drinking water: evidence from Bangladesh

Environmental Economics and Policy Studies - This study estimates health cost of salinity contamination in drinking water in the severe salinity affected three south-western districts of...     

Adaptation to climate change as resilience for urban extreme poor: lessons learned from targeted asset transfers programmes in Dhaka city of Bangladesh

This paper aims to identify how targeted asset transfers help to build adaptive capacity and adaptive actions of the urban extreme poor to climate change phenomena. This paper explores the theoretical debates of community-based adaptation approach and failure of such approach to address urban extreme poor. The empirical evidence of these theoretical debates will be drawn from two informal settlements of Dhaka city, where a targeted asset transfer project has been implementing since 2009. This paper explains that urban extreme poor usually work as unskilled labour and lack different livelihood capitals; and climate change is an increasingly important influence exacerbating an already vulnerable livelihood context. There is growing recognition in the literature that poor urban people and communities are adapting to climate change in physical and behavioural terms. But, in the case of urban extreme poor these adaptation approaches are delivering short-term survival strategies disregarding the notion of wellbeing in the medium to long-term perspectives. It is also evident that community level initiatives structurally reproduce the exclusion of the urban extreme poor. However, poverty literatures acknowledge that poverty-centred approaches could help to reduce vulnerability. As urban extreme poor are significantly more resource constrained, it is reasonable to assert that targeted asset transfers could be a poverty-centred adaptation approach in a changing climate. Targeted asset transfers approaches are the outcomes of recent social protection revolution that especially consider accumulation of physical, financial, human, and social capital in order to build adaptive capacity of the urban extreme poor. This adaptive capacity of the extreme poor may facilitate adjustments in assets, livelihoods, behaviours, and technologies in order to reduce future climate vulnerability. In this context, this paper seeks to answer whether targeted asset transfer approaches can be considered as effective poverty-centred adaptation approaches for the urban extreme poor or not.     

Prospect of castor oil biodiesel in Bangladesh: Process development and optimization study

In this study, castor oil (CO) has been investigated as a potential source for biodiesel production in Bangladesh. Castor oil has been extracted from the seeds by mechanical press and the Soxhlet extraction method. Maximum oil content of 55.7% has been found by the Soxhlet extraction method. The physicochemical properties such as free fatty acid (FFA) content, kinematic viscosity, saponification value, and density of the oil have been measured by different standard methods. The FFA content and viscosity have been found considerably higher such as 33.5% and 253 mm²/s, respectively. Biodiesel has been prepared using a three-step method comprising of saponification of oil followed by acidification of the soap and esterification of FFA. The overall yield of FFA from CO is found to be around 89.2%. The final step is esterification that produces fatty acid methyl ester (FAME) and a maximum 97.4% conversion of FFA to biodiesel has been observed. The effect of the oil to methanol molar ratio, catalyst concentration, reaction temperature, and time has been investigated for esterification reaction and optimized using the response surface methodology. ¹H NMR of crude castor oil and castor oil methyl ester (COME) was studied and analyzed that confirms the complete conversion of castor oil to biodiesel. Finally, the biodiesel, produced under optimum conditions, was characterized using the various standard method and found comparable with petro-diesel and biodiesel standard.     

Fishers’ local knowledge on impact of climate change and anthropogenic interferences on Hilsa fishery in South Asia: evidence from Bangladesh

The anadromous fish species Hilsa (Tenualosa ilisha) constitutes the largest single fishery in Bangladesh and West Bengal, India. River Meghna is the important habitat for Hilsa as the major breeding and nursing grounds are situated along this portion of the river. In this paper, we investigate fishers’ perceptions on effect of climate change and anthropogenic impact on Hilsa fishery at lower Meghna. Fishers’ ecological knowledge indicates that the stock of Hilsa is declining due to several adverse climatic conditions such as increased water temperature, salinity intrusion and low freshwater discharge from upstream. Fishers believe that dams and polders have immense effect on river sedimentation which already blockade several upward migratory route of Hilsa. Fishers’ experience shows that intensity of coastal cyclone is gradually increasing, which causes severe physical and economical damage. The study also indicates that the major constraints to adopt with the change situation are low level of human capital and restricted access to the formal credit system. Therefore, incorporation of local knowledge in governmental policy formulation and public support to improve human skill are essential for the adaptive management.