Microplastics are widely used to manufacture diverse products such as textiles, skin care products, and household products such as detergents and soaps. However, microplastic pollution and its potential health risks are raising concerns worldwide. This study characterized and determined the safety of microplastics in water and sediments obtained from three locations, namely Ibeshe, Amuwo Odofin, and Ojo along Badagry lagoon, Lagos, Nigeria. The samples of the lagoon's surface water and sediments were treated and analyzed for the abundance of microplastics, as well as their shapes, sizes, and types of polymers. The risk index of the polymers in the microplastics was also estimated. Microplastics were found to be more abundant (p ≤ 0.05) in the sediments (283–315 particles/kg) than in the surface water (108–199 particles/L). In both the water and sediments at all the locations, the dominant shapes were fibers (52%–90%), followed by fragments (3%–32%) and films (1%–25%). In order of significance, the microplastic size range of 0-100µm and 100-500µm dominated the surface water, while the size range of 1000-5000µm and 500-1000µm dominated the sediments at all the locations. The dominant polymers in both the water and sediments at all the locations were polyethylene, polypropylene, and polyamide, while the least was polystyrene. In both the water and sediments at all the locations, the dominant risk score among the polymers is III (moderate risk). The results obtained suggest that microplastic pollution poses environmental and health risks to the lagoon, aquatic organisms, and humans. As such, the lagoon required microplastic remediation and control.

This study aimed at quantifying the heavy metal levels in soils and vegetables sampled from five suburban regions of Nairobi, Kenya. Using inductively coupled plasma- mass spectrometry (ICP-MS) the metals were quantified from the samples. The assayed heavy metals including Cd, Cr, Co. Cu, Fe, Hg, Mn, Ni, Pb, Zn and the metalloid arsenic were elevated beyond the reference values in both soils and vegetables. High pollutant levels in soils were affiliated to use of industrial and domestic wastewater for irrigation, application of heavy metal containing agrochemicals and geogenic sources of the pollutants. In collard leaves, the uptake of contaminated water via the roots and subsequent accumulation in the leaves was attributable to the observed results. The total hazard quotient (THQ) and hazard index (HI) as a result of arsenic and Hg was >1 in all sampled sites and >10, respectively for both indices and heavy metals. Similarly, the cancer risk (CR) and target cancer risk (TCR) from consumption of collard was greater than the recommended levels of 10-6 and 10-4, respectively with exception of Pb. The indices were indicative of negative non-carcinogenic and carcinogenic effects of consuming the vegetables to the community of the study area. The results of the study, though preliminary, suggest the need to safeguard the health of communities in the study area to ensure that they do not consume heavy metal contaminated vegetables due to the established health effects of such pollutants.

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.

Incidental zinc sulfide nanoparticles (nano-ZnS) are spread on soils through organic waste (OW) recycling. Here we performed soil incubations with synthetic nano-ZnS (3 nm crystallite size), representative of the form found in OW. We used an original set of techniques to reveal the fate of nano-ZnS in two soils with different properties. 68Zn tracing and nano-DGT were combined during soil incubation to discriminate the available natural Zn from the soil, and the available Zn from the dissolved nano-68ZnS. This combination was crucial to highlight the dissolution of nano-68ZnS as of the third day of incubation. Based on the extended X-ray absorption fine structure, we revealed faster dissolution of nano-ZnS in clayey soil (82% within 1 month) than in sandy soil (2% within 1 month). However, the nano-DGT results showed limited availability of Zn released by nano-ZnS dissolution after 1 month in the clayey soil compared with the sandy soil. These results highlighted: (i) the key role of soil properties for nano-ZnS fate, and (ii) fast dissolution of nano-ZnS in clayey soil. Finally, the higher availability of Zn in the sandy soil despite the lower nano-ZnS dissolution rate is counterintuitive. This study demonstrated that, in addition to nanoparticle dissolution, it is also essential to take the availability of released ions into account when studying the fate of nanoparticles in soil.

Conservation agriculture through no-till based on cropping systems with high biomass-C input, is a strategy to restoring the carbon (C) lost from natural capital by conversion to agricultural land. We hypothesize that cropping systems based on quantity, diversity and frequency of biomass-C input above soil C dynamic equilibrium level can recover the natural capital. The objectives of this study were to: i) assess the C-budget of land use change for two contrasting climatic environments, ii) estimate the C turnover time of the natural capital through no-till cropping systems, and iii) determine the C pathway since soil under native vegetation to no-till cropping systems. In a subtropical and tropical environment, three types of land use were used: a) undisturbed soil under native vegetation as the reference of pristine level; b) degraded soil through continuous tillage; and c) soil under continuous no-till cropping system with high biomass-C input. At the subtropical environment, the soil under continuous tillage caused loss of 25.4 Mg C ha−1 in the 0–40 cm layer over 29 years. Of this, 17 Mg C ha−1 was transferred into the 40–100 cm layers, resulting in the net negative C balance for 0–100 cm layer of 8.4 Mg C ha−1 with an environmental cost of USD 1968 ha−1. The 0.59 Mg C ha−1 yr−1 sequestration rate by no-till cropping system promote the C turnover time (soil and vegetation) of 77 years. For tropical environment, the soil C losses reached 27.0 Mg C ha−1 in the 0–100 cm layer over 8 years, with the environmental cost of USD 6155 ha−1, and the natural capital turnover time through C sequestration rate of 2.15 Mg C ha−1 yr−1 was 49 years. The results indicated that the particulate organic C and mineral associate organic C fractions are the indicators of losses and restoration of C and leading C pathway to recover natural capital through no-till cropping systems.

Chlordecone (CLD), was widely applied in banana fields in the French West Indies from 1972 to 1993. The WISORCH model was constructed to assess soil contamination by CLD and estimated that it lasts from 100 to 600 years, depending on leaching intensity and assuming no degradation. However, recent studies demonstrated that CLD is degraded in the environment, hence questioning the reliability of previous estimations. This paper shows how to improve the model and provides insights into the long-term dissipation of CLD. In-situ observations were made in nearly 2545 plots between 2001 and 2020, and 17 plots were sampled at two dates. Results of soil analyses showed an unexpected 4-fold decrease in CLD concentrations in the soil, in contrast to simulations made using the first version of WISORCH at the time. Neither erosion, nor CLD leaching explained these discrepancies. In a top-down modeling approach, these new observations of CLD concentrations led us to implement a new dissipation process in the WISORCH model that corresponds to a DT50 dissipation half-life of 5 years. The new version of the improved model allowed us to update the prediction of the persistence of soil pollution, with soil decontamination estimated for the 2070s. This development calls for re-evaluation of soil pollution status. Further validation of the new version of WISORCH is needed so it can contribute to crop management on contaminated soil.

We simulate the combined natural and pollutant-induced survival of early life stages of NEA cod and haddock, and the impact on the adult populations in response to the time of a major oil spill in a single year. Our simulations reveal how dynamic ocean processes, controlling both oil transport and fate and the frequency of interactions of oil with drifting fish eggs and larvae, mediate the magnitude of population losses due to an oil spill. The largest impacts on fish early life stages occurred for spills initiated in Feb–Mar, concomitant with the initial rise in marine productivity and the earliest phase of the spawning season. The reproductive health of the adult fish populations was maintained in all scenarios. The study demonstrates the application of a simulation system that provides managers with information for the planning of development activities and for the protection of fisheries resources from potential impacts. | An annual profile of the impacts of simulated oil spills on the Northeast Arctic cod and haddock fisherie | publishedVersion

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.

We simulate the combined natural and pollutant-induced survival of early life stages of NEA cod and haddock, and the impact on the adult populations in response to the time of a major oil spill in a single year. Our simulations reveal how dynamic ocean processes, controlling both oil transport and fate and the frequency of interactions of oil with drifting fish eggs and larvae, mediate the magnitude of population losses due to an oil spill. The largest impacts on fish early life stages occurred for spills initiated in Feb–Mar, concomitant with the initial rise in marine productivity and the earliest phase of the spawning season. The reproductive health of the adult fish populations was maintained in all scenarios. The study demonstrates the application of a simulation system that provides managers with information for the planning of development activities and for the protection of fisheries resources from potential impacts | An annual profile of the impacts of simulated oil spills on the Northeast Arctic cod and haddock fisheries | publishedVersion