Accumulation of organochlorines in the European clam (Ruditapes decussatus) and sediment of the Oualidia lagoon (Morocco).

This study focused on the analysis of organochlorine pesticides and PCBs in tissue samples of the clam, Ruditapes decussatus, in the Oualidia lagoon. Tissue assays were conducted during February to December 2005 and sediment (October 2005) was also tested. 13 organochlorine compounds and eight PCBs congeners were investigated, is HCB, γ-HCH, chlordane, cis-chlordane and trans-nonachlor, DDT and its metabolites DDD, DDE, heptachlor, its epoxide, mirex and PCBs (PCB28 + 50, PCB52, PCB101, PCB 118, PCB138, PCB153, PCB180). Analysis of these compounds was performed using a gas chromatography capillary column and an electron capture detector. Organochlorine contamination of clams and sediments in the lagoon did not exceed tolerable thresholds according to European standards. The levels of tPCB, tDDT and tOCP in clams are high at 49.4, 22.2, and 7.1 ng g(-1) dw respectively. Concentrations of trans nonachlor and mirex are low compared to other chlorinated pesticides. PCB28 + 50, PCB52 and PCB101 show typical values in sediment, at 18.5, 10.8 and 17.8 ng g(-1) dw respectively.

Long-range transport of pollutants to the Falkland Islands and Antarctica: evidence from lake sediment fly ash particle records.

(210)Pb-dated sediment cores taken from lakes on the Falkland Islands, the South Orkney Islands, and the Larsemann Hills in Antarctica were analyzed for fly ash particles to assess the temporal record of contamination from high temperature fossil-fuel combustion sources. Very low, but detectable, levels were observed in the Antarctic lakes. In the Falkland Island lakes, the record of fly ash extended back to the late-19th century and the scale of contamination was considerably higher. These data, in combination with meteorological, modeling, and fossil-fuel consumption data, indicate most likely sources are in South America, probably Chile and Brazil. Other southern hemisphere sources, notably from Australia, contribute to a background contamination and were more important historically. Comparing southern polar data with the equivalent from the northern hemisphere emphasizes the difference in contamination of the two circumpolar regions, with the Falkland Island sites only having a level of contamination similar to that of northern Svalbard.

Achievements, challenges and global implications of China's carbon neutral pledge.

China has been committed to achieving carbon neutrality by 2060. China's pledge of carbon neutrality will play an essential role in galvanising global climate action, which has been largely deferred by the Covid-19 pandemic. China's carbon neutrality could reduce global warming by approximately 0.2-0.3 °C and save around 1.8 million people from premature death due to air pollution. Along with domestic benefits, China's pledge of carbon neutrality is a "game-changer" for global climate action and can inspire other large carbon emitters to contribute actively to mitigate carbon emissions, particularly countries along the Belt and Road Initiative (BRI) routes. In order to achieve carbon neutrality by 2060, it is necessary to decarbonise all sectors in China, including energy, industry, transportation, construction, and agriculture. However, this transition will be very challenging, because major technological breakthroughs and large-scale investments are required. Strong policies and implementation plans are essential, including sustainable demand, decarbonizing electricity, electrification, fuel switching, and negative emissions. In particular, if China can peak carbon emissions earlier, it can lower the costs of the carbon neutral transition and make it easier to do so over a longer time horizon. China's pledge of carbon neutrality by 2060 and recent pledges at the 26th UN Climate Change Conference of the Parties (COP26) are significant contributions and critical steps for global climate action. However, countries worldwide need to achieve carbon neutrality to keep the global temperature from growing beyond the level that will cause catastrophic damages globally.

Evidence of North Africa's green revolution preserved in sedimentary organic matter deposited in three coastal lagoons.

Because of longer residence times and limited mixing in coastal lagoons, the impacts of anthropogenic nutrient loading to lagoon food webs are often more pronounced than in other coastal ecosystems. For these reasons, many lagoons also provide an excellent environment for the deposition and accumulation of organic matter (OM). Sediment cores were retrieved from three North African lagoons to provide records of recent environmental changes. We measured percentage nitrogen (%N), nitrogen stable isotope values (delta15N), and percentage organic matter (%OM), and we used radiometric dating techniques (210Pb, 137Cs) to examine the evidence for the intensification of upstream agricultural practices in sediment cores from Lake Manzala (Egypt), Ghar El Melh Lagoon (Tunisia), and Lagune de Nador (Morocco). With the exception of one core collected near a sewage outfall, sediments from Lake Manzala clearly reflected the impact of agricultural intensification following completion of the Aswan High Dam and delta barrages in the mid-1960s to early 1970s. Both %N and %OM more than doubled in three Manzala sediment cores, and delta15N values declined from 5 per thousand to < 1 per thousand. These changes reflect the increasing use of synthetic fertilizers (delta15N approximately 0 per thousand) from the 1960s to the present. Sediments from Ghar El Melh show a similar trend, with %N more than tripling, %OM increasing by 50%, and delta15N declining from 6 per thousand to 2 per thousand since 1965. These changes are consistent with the increasing use of water from a nearby river for crop irrigation and agricultural fertilizer use. Lagune de Nador receives relatively little agricultural drainage water, and core data did not show the same trends as Manzala and Ghar El Melh. Overall, the sediment core data from these systems reflect environmental shifts in the quantity, quality, and isotope signature of the deposited organic matter and confirm the concerns of local scientists and environmental managers that eutrophication has had dramatic impacts on the coastal ecosystems, particularly at the Egyptian and Tunisian sites.

Diversity and abundance of Lepidoptera populations in the Theniet El Had National Park (Algeria).

An inventory of Lepidoptera in the Theniet El Had National Park (PNTEH), Algeria, revealed 86 taxa, both butterflies and moths. The specimens were collected in 68 localities distributed over ten cantons within the park in the period 2015-2017. A preliminary faunistic list is compiled as a base-line contribution to the study of adult Lepidoptera in this park. In total, 3139 specimens were collected. The moths are clearly well diversified, with 14 families and 49 species obtained from a total of 1485 adult specimens. The butterflies are represented by 5 families with 37 species and 1654 specimens. A total of 8 families are reported for the first time from this park, in order of abundance: Zygaenidae, Hesperiidae, Crambidae, Alucitidae, Heterogynidae, Sesiidae, Oecophoridae, and Cossidae. Also 61 species are recorded here for the first time for the park. The most diverse family is Nymphalidae with 15 taxa (23% of the total species). On the other hand, the Erebidae are represented by 894 specimens (28.5% of the total number of specimens. Within the Erebidae, the genus Catocala contains the highest number of individuals (794 specimens). The canton of Pré-Ben Chouhra is quantitatively the best represented with 625 specimens (19.9% of the total number of specimens collected) and the Nursery canton as the richest in lepidopteran species with 72 species observed. The diversity indices (H' and Hmax.) and the equitability index (E), calculated for the 10 cantons indicate that lepidopteran species are diverse in each station.

Waste management, informal recycling, environmental pollution and public health.

With rapid population growth, especially in low-income and middle-income countries, the generation of waste is increasing at an unprecedented rate. For example, annual global waste arising from waste electrical and electronic equipment alone will have increased from 33.8 to 49.8 million tonnes between 2010 and 2018. Despite incineration and other waste treatment techniques, landfill still dominates waste disposal in low-income and middle-income countries. There is usually insufficient funding for adequate waste management in these countries and uptake of more advanced waste treatment technologies is poor. Without proper management, many landfills represent serious hazards as typified by the landslide in Shenzhen, China on 20 December 2015. In addition to formal waste recycling systems, approximately 15million people around the world are involved in informal waste recycling, mainly for plastics, metals, glass and paper. This review examines emerging public health challenges, in particular within low-income and middle-income countries, associated with the informal sector. While informal recyclers contribute to waste recycling and reuse, the relatively primitive techniques they employ, combined with improper management of secondary pollutants, exacerbate environmental pollution of air, soil and water. Even worse, insufficient occupational health measures expose informal waste workers to a range of pollutants, injuries, respiratory and dermatological problems, infections and other serious health issues that contribute to low life expectancy. Integration of the informal sector with its formal counterparts could improve waste management while addressing these serious health and livelihood issues. Progress in this direction has already been made notably in several Latin American countries where integrating the informal and formal sectors has had a positive influence on both waste management and poverty alleviation.