Plastic usage increases year by year, and the growing trend is projected to continue. However as of 2017, only 9% of the 9 billion tons of plastic ever produced had been recycled leaving large amounts of plastics to contaminate the environment, resulting in important negative health and economic impacts. Curbing this trend is a major challenge that requires urgent and multifaceted action. Based on scientific and gray literature mainly published during the last 10 years, this review summarizes key solutions currently in use globally that have the potential to address at scale the plastic and microplastic contaminations from source to sea. They include technologies to control plastics in solid wastes (i.e. mechanical and chemical plastic recycling or incineration), in-stream (i.e. booms and clean-up boats, trash racks, and sea bins), and microplastics (i.e. stormwater, municipal wastewater and drinking water treatment), as well as general policy measures (i.e. measures to support the informal sector, bans, enforcement of levies, voluntary measures, extended producer responsibility, measures to enhance recycling and guidelines, standards and protocols to guide activities and interventions) to reduce use, reuse, and recycle plastics and microplastics in support of the technological options. The review discusses the effectiveness, capital expenditure, and operation and maintenance costs of the different technologies, the cost of implementation of policy measures, and the suitability of each solution under various conditions. This guidance is expected to help policymakers and practitioners address, in a sustainable and cost-efficient way, the plastic and microplastic management problem using technologies and policy instruments suitable in their local context.

In the face of emerging and re-emerging diseases, novel and innovative approaches to population scale surveillance are necessary for the early detection and quantification of pathogens. The last decade has seen the rapid development of wastewater and environmental surveillance (WES) to address public health challenges, which has led to establishment of wastewater-based epidemiology (WBE) approaches being deployed to monitor a range of health hazards. WBE exploits the fact that excretions and secretions from urine, and from the gut are discharged in wastewater, particularly sewage, such that sampling sewage systems provides an early warning system for disease outbreaks by providing an early indication of pathogen circulation. While WBE has been mainly used in locations with networked wastewater systems, here we consider its value for less connected populations typical of lower-income settings, and assess the opportunity afforded by pit latrines to sample communities and localities. We propose that where populations struggle to access health and diagnostic facilities, and despite several additional challenges, sampling unconnected wastewater systems remains an important means to monitor the health of large populations in a relatively cost-effective manner.

Wastewater irrigation may introduce antibiotic residues in the soil-plant systems. This study aimed to investigate the uptake of tetracyclines by spinach and collard greens and assess associated ecological and human health risks. Synthetic wastewater spiked with 1 ppm and 10 ppm of oxytetracycline, doxycycline, and tetracycline was used to grow vegetables in a greenhouse pot experiment. The uptake and accumulation of the tetracyclines were low and residual concentrations in the soil were negligible. All the tetracyclines were detected at concentrations ranging from 1.68 to 51.41 μg/g (spinach) and 1.94–30.95 μg/g (collard greens). The accumulation rate was in a dose-response scenario with a bioconcentration factor of 6.34 mL/kg (spinach) and 2.64 mL/kg (collard greens). Oxytetracycline had the highest accumulation in leaves, followed by doxycycline and tetracycline, and the residual concentrations followed the same order. The highest residual concentration was in soils receiving 10 ppm oxytetracycline. Residual concentrations in the soil were lower than accumulated levels and exerted negligible ecological risks. Tetracyclines accumulation in spinach significantly differed between the vegetables demonstrating a subspecies difference in uptake and accumulation. Ecological risk quotient (RQ) and human health risk quotient (HQ) were below thresholds that would exert toxicity and resistance selection impacts. Although RQs and HQs are low (<0.1), this study shows that the vegetables accumulate tetracyclines from irrigation water, posing plausible human health risks to allergic individuals. Similarly, the ecological risks cannot be ignored because the synergistic and antagonistic effects of sublethal concentrations can perturb ecosystem processes.

The in-depth knowledge on management and reducing annual acidic pollution is important for improving the sustainable livelihood of people living in areas with acid sulphate soils (ASS). This study involved a long-term (2001-2006), large-scale canal water quality monitoring network (87 locations) and a field experiment at nine sites to quantify the dynamic variability of acidic pollution and its source in a coastal area with ASS in the Mekong River Delta of Vietnam. Widespread acidic pollution (pH <5) of surface water occurred at the beginning of the rainy season, while pH of the canal water remained high (7-8) at the end of the rainy season and during the dry season. The study identified canal embankment deposits, made of ASS spoils from canal dredging/excavation, as the main source of acidic pollution in the surrounding canal network. The findings suggested that there was a linkage between the amount of acidic loads into canal networks and the age of the embankment deposits. The most acute pollution (pH ~ 3) occurred in canals with sluggish tidal water flow, at 1-2 years after the deposition of excavated spoils onto the embankments in ASS. The amount of acidic loads transferred to the canal networks could be quantified from environmental parameters, including cumulative rainfall, soil type and age of embankment deposits. The study implied that dredging/excavation of canals in ASS areas must be carried out judiciously as these activities may increase the source of acidic pollution to the surrounding water bodies.

This paper describes a study that was aimed at optimizing the pelletization of fecal sludge-based fertilizers for agricultural use. The process developed is easy to implement and increases the marketability of the products while also addressing a serious health and environmental challenge. The study took place during the period 2011-2012 in Ghana. The fecal sludge, rich in nutrients and organic matter, was dried and used to produce five different fertilizers (i.e., four formulations of compost and one with gamma irradiated material). Each material was then pelletized using locally constructed machinery. Key operating parameters, such as moisture content (10-55% in mass), binder type (clay or starch) and concentration (0-10% in mass), were varied and their impacts on the characteristics of pellets (e.g., amount of fine materials generated, length distribution or stability of pellets, and pellet disintegration rate) were also followed. Given the low analyzing capabilities of developing countries, some simple analytical methods were developed and used to compare pellets produced under different conditions. The results confirmed that the addition of 3% of pregelatinized starch is recommended during pelletization of fecal sludge-based fertilizers. Applicable moisture contents were also identified per fertilizer type, and were found to comprise between 21 and 43%.

Fertilizer, though one of the most essential inputs for increasing agricultural production, is a leading cause of nitrous oxide emissions from agriculture, contributing significantly to global warming. Therefore, understanding factors affecting farmers’ use of fertilizers is crucial to develop strategies to improve its efficient use and to minimize its negative impacts. Using data from 2528 households across the Indo-Gangetic Plains in India, Nepal, and Bangladesh, this study examines the factors affecting farmers’ use of organic and inorganic fertilizers for the two most important cereal crops – rice and wheat. Together, these crops provide the bulk of calories consumed in the region. As nitrogen (N) fertilizer is the major source of global warming and other environmental effects, we also examine the factors contributing to its overuse. We applied multiple regression models to understand the factors influencing the use of inorganic fertilizer, Heckman models to understand the likelihood and intensity of organic fertilizer (manure) use, and a probit model to examine the over-use of N fertilizer. Our results indicate that various socio-economic and geographical factors influence the use of organic and inorganic fertilizers in rice and wheat. Across the study sites, N fertilizer over-use is the highest in Haryana (India) and the lowest in Nepal. Across all locations, farmers reported a decline in manure application, concomitant with a lack of awareness of the principles of appropriate fertilizer management that can limit environmental externalities. Educational programs highlighting measures to improving nutrient-use-efficiency and reducing the negative externalities of N fertilizer over-use are proposed to address these problems.

Little is known about the occurrence of emerging pollutants (EPs) in waters in the Middle East and North Africa (MENA) region despite the extensive use of low-quality water there. Available data dealing with the sources, occurrence and removal of EPs within the MENA region in different categories of water is collected, presented and analyzed in this literature review. According to the collected database, the occurrence and removal efficiency of EPs in the water matrix in the MENA region is available, respectively, for 13 and six countries of the 18 in total; no available data is registered for the rest. Altogether, 290 EPs have been observed in different water matrices across the MENA countries, stemming mainly from industrial effluents, agricultural practices, and discharge or reuse of treated wastewater (TWW). Pharmaceutical compounds figure among the most frequently reported compounds in wastewater, TWW, surface water, and drinking water. Nevertheless, pesticides are the most frequently detected pollutants in groundwater. Worryingly, 57 cases of EPs have been reported in different fresh and drinking waters, exceeding World Health Organization (WHO) and European Commission (EC) thresholds. Overall, pharmaceuticals, organic compounds, and pesticides are the most concerning EP groups. The review revealed the ineffectiveness of treatment processes used in the region to remove EPs. Negative removals of some EPs such as carbamazepine, erythromycin, and sulfamethoxazole were recorded, suggesting their possible accumulation or release during treatment. This underlines the need to set in place and strengthen control measures, treatment procedures, standards, and policies for such pollutants in the region.

On March 11 2011, a tsunami caused by a magnitude 9.0 earthquake devastated the northeastern coast of Honshu, Japan.The present study was conducted to assess environmental health risks of the areas affected and socio-psychological status of the dislocated people in Ishinomaki. Samples of sludge, water, flies and rodents were collected in 20 urban neighborhood associations affected by the tsunami in July and August 2011, and in August 2012. A socio-psychological survey was conducted in two urban and one rural temporary housing complexes in 2012. Animal feed concentrates and fish from damaged factories were scattered along the coast which caused a strong odor and great number of flies. Removal of fish and feed along with spraying insecticides reduced the odor and the number of flies by August 2011. The sludge and water samples contained potentially hazardous bacteria, but none were highly pathogenic. Heavy metals in sludge were not in alarming quantities. A rodent was captured in one unit in August 2011, and monitoring in two units found that the log number of rodents captured increased significantly over time (slope=0.08, p = 0.005). In temporary housing complexes, those who originally lived in rural fishing villages wished to return to their homes more (64.2%, 9/14) than in urban areas (30.6%, 11/36, p = 0.06). Risk factors for depression included absence of friends (p = 0.011) or trusted person to counsel in the housing complexes (p = 0.003) and illness of the respondent or a family member (p = 0.003). In conclusion, overall environmental health risk was acceptable for living, and monitoring of rodents population was recommended. In addition, psychological and economical support was needed for evacuees in temporary housing complexes.

It is essential to increase food production to meet the projected population increase while reducing environmental loads. Biological nitrification inhibition (BNI)-enabled wheat genetic stocks are under development through chromosome engineering by transferring chromosomal regions carrying the BNI trait from a wild relative (Leymus racemosus (Lam.) Tzvelev) into elite wheat varieties; field evaluation of these newly developed BNI-wheat varieties has started. Ten years from now, BNI-enabled elite wheat varieties are expected to be deployed in wheat production systems. This study aims to evaluate the impacts of introducing these novel genetic solutions on life cycle greenhouse gas (LC-GHG) emissions, nitrogen (N) fertilizer application rates and N-use efficiency (NUE). Scenarios were developed based on evidence of nitrification inhibition and nitrous oxide (N2O) emission reduction by BNI crops and by synthetic nitrification inhibitors (SNIs), as both BNI-wheat and SNIs slow the nitrification process. Scenarios including BNI-wheat will inhibit nitrification by 30% by 2030 and 40% by 2050. It was assumed that N fertilizer application rates can potentially be reduced, as N losses through N2O emissions, leaching and runoff are expected to be lower. The results show that the impacts from BNI-wheat with 40% nitrification inhibition by 2050 are assessed to be positive: a 15.0% reduction in N fertilization, a 15.9% reduction in LC-GHG emissions, and a 16.7% improvement in NUE at the farm level. An increase in ammonia volatilization had little influence on the reduction in LC-GHG emissions. The GHG emissions associated with N fertilizer production and soil N2O emissions can be reduced between 7.3 and 9.5% across the wheat-harvested area worldwide by BNI-wheat with 30% and 40% nitrification inhibition, respectively. However, the present study recommends further technological developments (e.g. further developments in BNI-wheat and the development of more powerful SNIs) to reduce environmental impacts while improving wheat production to meet the increasing worldwide demand.