Challenges, opportunities, and innovations for effective solid waste management during and post COVID-19 pandemic.

The crisis brought upon by the COVID-19 pandemic has altered global waste generation dynamics and therefore has necessitated special attention. The unexpected fluctuations in waste composition and quantity also require a dynamic response from policymakers. This study highlights the challenges faced by the solid waste management sector during the pandemic and the underlying opportunities to fill existing loopholes in the system. The study presents specific cases for biomedical waste, plastic waste, and food waste management - all of which have been a major cause of concern during this crisis. Further, without active citizen participation and cooperation, commingled virus-laden biomedical waste with the regular solid waste stream pose significant negative health and safety issues to sanitation workers. Single-use plastic usage is set to bounce back due to growing concerns of hygiene, particularly from products used for personal protection and healthcare purposes. It is expected that household food waste generation may reduce due to increased conscious buying of more non-perishable items during lockdown and due to concerns of food shortage. However, there is a chance of increase in food waste from the broken supply chains such as food items getting stuck on road due to restriction in vehicle movements, lack of workers in the warehouse for handling the food products, etc. The study also stresses the need for building localized resilient supply chains to counter such situations during future pandemics. While offering innovative solutions to existing waste management challenges, the study also suggests some key recommendations to the policymakers to help handle probable future pandemics if any holistically.

Are we underestimating stormwater? Stormwater as a significant source of microplastics in surface waters.

Stormwater represent a critical pathway for transporting microplastics (MPs) to surface waters. Due to complex dynamics of MPs in stormwater, its dispersion, weathering, risk, and transport are poorly understood. This review bridges those gaps by summarizing the latest findings on sources, abundance, characteristics, and dynamics involved in stormwater MP pollution. Weathering starts before or after MPs enter stormwater and is more pronounced on land due to continuous heat and mechanical stress. Land use patterns, rainfall intensity, MPs size and density, and drainage characteristics influence the transport of MPs in stormwater. Tire and road wear particles (TRWPs), littering, and road dust are major sources of MPs in stormwater. The concentrations of MPs varies from 0.38-197,000 particles/L globally. Further MP concentrations showed regional variations, highlighting the importance of local monitoring efforts needed to understand local pollution sources. We observed unique signatures associated with the shape and color of MPs. Fibers and fragments were widely reported, with transparent and black being the predominant colors. We conclude that the contribution of stormwater to MP pollution in surface waters is significantly greater than wastewater treatment plant effluents and demands immediate attention. Field and lab scale studies are needed to understand its behavior in stormwater and the risk posed to the downstream water bodies.

Drinking hot beverages from paper cups: Lifetime intake of microplastics.

Microplastics (MPs) have been found in many packaged food products such as salt, tea bags, milk, and fish. In a previous study by this group, MPs were found to leach into hot water from the plastic lining of disposable paper cups. No studies were found in the literature quantifying health risks or lifetime intake of MPs. At present, it is not possible to quantify health risks due to MPs because dose-response and toxicity assessments are not available. Therefore, the objective of the current study was to assess the intake of MPs and associated contaminants like fluoride that are released into these hot beverages. MPs in the previous study were quantified in terms of particle counts only and a simple method was adopted in the present study to convert the microplastics count into its respective mass. Chronic daily intake (CDI) and lifetime intake (LTI) of MPs through the ingestion pathway were calculated. CDI and Hazard Quotient (HQ) due to fluoride ingestion were also estimated following USEPA guidelines. Monte Carlo (MC) simulations were used to account for the variability in input variables such as concentration of MPs, body weight, averaging time, exposure duration, exposure frequency and ingestion rate to evaluate the impact on CDI and LTI values. The CDI was used to estimate the LTI of MPs and HQ for fluoride ingestion. MC simulations with 100,000 iterations resulted in an average CDI of 0.03 ± 0.025 mg of microplastic per kg of body weight per day and 7.04 ± 8.8 µg fluoride per kg body weight per day. This study takes us one step closer to estimating the human health risk due to the ingestion of microplastics and other contaminants through food items.

Preliminary investigation on effects of size, polymer type, and surface behaviour on the vertical mobility of microplastics in a porous media.

Due to the ubiquitous nature of microplastic (MP), knowledge of its fate and migration in subsurface environments like soil becomes extremely important to understand underlying ecological risk. The fate and migration of MP in subterranean settings like sand are governed by the retention/transport properties influenced by the interaction of sand and MPs. In this study, sand column experiments under simulated rainfall conditions were conducted for 180 days to assess the vertical migration of mixed MPs consisting of polypropylene (PP), polyethylene (PE), and polyethylene terephthalate (PET). Sand column experiments were subjected to 60 wet-dry cycles over 180 days. The effects of polymer type, microplastic size, sand particle size, and surface roughness on the migration of MPs were evaluated. Results showed that the smallest-sized fragmented PE particles had the highest migration potential compared to PET and PE. The ratios of the diameters of MP particles and sand particles (dMP/dsand) played a significant role in determining the penetration depth of the various sizes of MPs. The MP particles with dMP/dsand 0.11 showed greater penetration depth in sand media and were detected in the column effluent water after 60 days of a column run. In addition, surface roughness, low ionic strength water, irregularly shaped particles, and wet and dry cycles contributed to the migration of MPs in the sand column. Three new absorbance peaks corresponding to the hydroxyl, CO stretch, and carbonyl groups evolved in the extracted PE MPs sample from different depths, as shown by FTIR analysis, suggesting that PE MPs had been oxidised. XPS analysis revealed changes in the surface properties of the MPs, indicating that oxidation occurred at the top layer, causing structural deterioration of the PE MPs. However, oxidation of the surface bonds was restricted in the layers underneath due to a lack of oxygen. The finding of the study suggests that in a natural environment, such accumulation and migration of MPs in sandy soil can increase the possibilities to the underlying groundwater contamination.

Cigarettes butt littering: The story of the world's most littered item from the perspective of pollution, remedial actions, and policy measures.

Cigarettes butt (CB) is one of the most littered items on the planet. This paper critically analyzes the factors responsible for CB littering, and associated environmental ramifications, and reviews all the possible technical, behavioural, and policy-based solutions. Even while smoking has declined globally, middle-income nations have seen an increase in consumption, which may be related to increased affordability and a lack of public awareness. The smokers' individual beliefs and habits, environmental ignorance, covert littering as a result of social taboos associated with smoking, and behavioural gaps between intention and action might all be contributing factors to CBs' littering behaviour. The low biodegradability of cellulose acetate filters and toxic chemical leaching from CBs are the most important aspects of CB environmental toxicity. The small size and low economic value of CB contribute to the inefficiencies of current waste collection and management systems. The current research on CB valorisation includes fired-clay bricks, asphalt concrete, biofilms, sound absorber, cellulose pulp, pesticides, and insecticides as downstream mitigation strategies. This study highlights the urgent need for policymakers to enforce regulations enabling innovative cigarette designs, the creation of deposit-refund schemes, extended producer responsibility and stringent waste collection mechanisms. Adopting gentler marketing strategies and non-confrontational behavioural nudges could result in an overall reduction in CB pollution.

Microplastics and other harmful substances released from disposable paper cups into hot water.

Disposable paper cups are popular for consuming beverages. These paper cups have an interior that is laminated with a hydrophobic film made of mostly plastic (polyethylene) and sometimes of copolymers. The objective of this study was to evaluate the degradation of these films as a result of exposure to hot water (85-90 °C). Due to deterioration of the films, ions like fluoride, chloride, sulfate, and nitrate were released into the water contained in the paper cups. Microplastic particles leaching into the liquid were identified and quantified. Fluorescence microscopy indicated the release of approximately 25,000 micron-sized microplastic particles into one cup of hot water in 15 min (100 ml) while scanning electron micrographs indicate 102 + 21.1 × 106 sub-micron-sized particles/ml into the same volume of liquid. Toxic heavy metals like Pb, Cr, and Cd were detected in the films which can be transferred into hot water. Elemental analysis shows a decrease in the percentage of elements like C, H, and N (by weight) due to exposure to hot water. Ingestion of microplastics, ions, and heavy metals regularly while consuming our daily dose of hot beverages like tea and coffee can expose us to potential health risks in the future.

Challenges and strategies for effective plastic waste management during and post COVID-19 pandemic.

The advent of the COVID-19 pandemic has enhanced the complexities of plastic waste management. Our improved, hyper-hygienic way of life in the fear of transmission has conveniently shifted our behavioral patterns like the use of PPE (Personal protective equipment), increased demand for plastic-packaged food and groceries, and the use of disposable utensils. The inadequacies and inefficiencies of our current waste management system to deal with the increased dependence on plastic could aggravate its mismanagement and leakage into the environment, thus triggering a new environmental crisis. Mandating scientific sterilization and the use of sealed bags for safe disposal of contaminated plastic wastes should be an immediate priority to reduce the risk of transmission to sanitation workers. Investments in circular technologies like feedstock recycling, improving the infrastructure and environmental viability of existing techniques could be the key to dealing with the plastic waste fluxes during such a crisis. Transition towards environmentally friendly materials like bioplastics and harboring new sustainable technologies would be crucial to fighting future pandemics. Although the rollbacks and relaxation of single-use plastic bans may be temporary, their likely implications on the consumer perception could hinder our long-term goals of transitioning towards a circular economy. Likewise, any delay in building international willingness and participation to curb any form of pollution through summits and agendas may also delay its implementation. Reduction in plastic pollution and at the same time promoting sustainable plastic waste management technologies can be achieved by prioritizing our policies to instill individual behavioral as well as social, institutional changes. Incentivizing measures that encourage circularity and sustainable practices, and public-private investments in research, infrastructure and marketing would help in bringing the aforementioned changes. Individual responsibility, corporate action, and government policy are all necessary to keep us from transitioning from one disaster to another.