This manuscript evaluates spatial and temporal variations of source contributions to ambient fine particulate matter (PM2.5) in Israeli, Jordanian, and Palestinian cities. Twenty-four hour integrated PM2.5 samples were collected every six days over a 1-year period (January to December 2007) in four cities in Israel (West Jerusalem, Eilat, Tel Aviv, and Haifa), four cities in Jordan (Amman, Aqaba, Rahma, and Zarka), and three cities in Palestine (Nablus, East Jerusalem, and Hebron). The PM2.5 samples were analyzed for major chemical components, including organic carbon and elemental carbon, ions, and metals, and the results were used in a positive matrix factorization (PMF) model to estimate source contributions to PM2.5 mass. Nine sources, including secondary sulfate, secondary nitrate, mobile, industrial lead sources, dust, construction dust, biomass burning, fuel oil combustion and sea salt, were identified across the sampling sites. Secondary sulfate was the dominant source, contributing 35% of the total PM2.5 mass, and it showed relatively homogeneous temporal trends of daily source contribution in the study area. Mobile sources were found to be the second greatest contributor to PM2.5 mass in the large metropolitan cities, such as Tel Aviv, Hebron, and West and East Jerusalem. Other sources (i.e. industrial lead sources, construction dust, and fuel oil combustion) were closely related to local emissions within individual cities. This study demonstrates how international cooperation can facilitate air pollution studies that address regional air pollution issues and the incremental differences across cities in a common airshed. It also provides a model to study air pollution in regions with limited air quality monitoring capacity that have persistent and emerging air quality problems, such as Africa, South Asia and Central America.

For the foreseeable future, industrial water demand will grow much faster than agriculture. The demand together with the urgency of wastewater treatment, will pose big challenges for most developing countries. We applied the bibliometric analysis combined with social network analysis and S-curve technique to quantitatively analyze 9413 publications related to industrial wastewater treatment in the Scientific Citation Index (SCI) and Social Sciences Citation Index (SSCI) databases from 1998 to 2019. The results showed that: (1) Publications on industrial wastewater treatment have increased from 120 in 1998 to 895 in 2019 with a steady annual increment rate, and researchers have focused more on the application and optimization of existing technologies. (2) China had the highest number of publications (n = 1651, 19.66% of global output) and was a core country in the international cooperation network, whereas the United States and European countries produced higher quality papers. (3) By analyzing the co-occurrence and clusters of keywords and comparing three wastewater treatment categories (physical, chemical, biological), adsorption (n = 1277), oxidation (n = 1085) and activated sludge process (n = 1288) were the top three techniques. Researchers have shifted their focus to treatment technologies for specific wastewater type, such as textile wastewater, pulp and paper wastewater, and pharmaceutical wastewater. The S-curve from articles indicates that physical and chemical treatment technologies are attached with great potential in the near future, especially adsorption and advanced oxidation, while the biological treatment technologies are approaching to the saturation stage. Different pattern is observed for the S-curve derived from patents, which stressed the limited achievement until now and further exploration in the field application for the three treatment categories. Our analysis provides information of technology development landscape and future opportunities, which is useful for decision makers and researchers who are interested in this area.

Since early 1980s, chemical pollution has become a serious environmental problem in rapidly developing China. This study reviewed the policy and legal framework for monitoring and management of chemical pollutants in China, with reference to the relevant experience in other jurisdictions. Although efforts in environmental monitoring of chemical contamination have been substantially increased over the last decade, China is lagging behind in terms of nationwide monitoring of chemical contamination in human population, and standardization of sampling and analytical protocols. While actively participating in various international treaties and conventions related to pollution control, China also has a very comprehensive set of environmental laws and policies. These include the newly enacted legislation on the control of new chemicals (i.e., China REACH) and the development of a set of National Environmental Standards. In addition to environmental education, these new measures will further enhance the control of chemical pollutants and facilitate effective law enforcement.

Paired indoor and outdoor concentrations of fine and coarse particulate matter (PM), PM2.5 reflectance [black carbon(BC)], and nitrogen dioxide (NO₂) were determined for sixteen weeks in 2008 at four elementary schools (two in high and two in low traffic density zones) in a U.S.–Mexico border community to aid a binational health effects study. Strong spatial heterogeneity was observed for all outdoor pollutant concentrations. Concentrations of all pollutants, except coarse PM, were higher in high traffic zones than in the respective low traffic zones. Black carbon and NO₂ appear to be better traffic indicators than fine PM. Indoor air pollution was found to be well associated with outdoor air pollution, although differences existed due to uncontrollable factors involving student activities and building/ventilation configurations. Results of this study indicate substantial spatial variability of pollutants in the region, suggesting that children’s exposures to these pollutants vary based on the location of their school.

Microplastic pollution in marine environment has been a growing public concern in recent years. This article analyzed the scientific literatures related to marine microplastics through a combination of social network analysis and bibliometrics. Researches related to microplastics have grown rapidly since 2011, with approximately two-thirds of the total number of articles published in the last three years. Researchers in United States and Europe have provided tremendous support, however, the efforts and progress of Chinese researchers cannot be ignored. Moreover, the international cooperation is getting closer, and related strategies are launched continuously. The results showed that Marine Pollution Bulletin is the most active journal. Through keyword analysis, we understand the development history and current hotspots of the whole microplastics researches, including ecological risks, interrelationship between microplastics and other pollutants, and detection methodology. Finally, some suggestions and perspectives for future microplastics research are provided.

In the marine environment, underwater noise is one of the most widespread input of man-made energy. Recently, the European Commission has stressed the necessity of establishing threshold levels as a target for the descriptor 11.2.1 “Continuous low frequency sounds” in the Marine Strategy Framework Directive (MSFD). In 2012, a monthly underwater noise monitoring programme was conducted in the Gulf of Trieste (Northern Adriatic Sea, Italy); the collected acoustic samples (frequency range: 10–20,000Hz) were analysed in the 1/3 octave bands. The stations have been further clustered following the 63 and 125Hz bands noise levels. Average SPL levels resulted similar to those previously computed for proximate areas, indicating that the Adriatic Sea sub-region experiences high noise pressure in the marine waters. In its turn this claims for a scientific and technical international cooperation, as requested by the EU programme. No seasonal variation in local noise levels has been found.

The outbreak of the COVID-19 pandemic has brought enormous challenges to the global marine environment. Various responses to the COVID-19 pandemic have led to increased marine pollution. Has the COVID-19 pandemic affected marine pollution research? This work comprehensively reviewed marine pollution publications in the Web of Science database before and during the COVID-19 pandemic. Results show that the COVID-19 outbreak has influenced the marine pollution research by: (i) increasing the number of publications; (ii) reshaping different countries' roles in marine pollution research; (iii) altering the hotspots of marine pollution research. The ranking of countries with high productivity in the marine pollution research field changed, and developed economies are the dominant players both before and after the outbreak of the COVID-19 pandemic in this field. Other high-productivity countries, with the exception of China, have higher international cooperation rates in marine pollution research than those before the pandemic. Microplastic pollution has been the biggest challenge of marine pollution and has been aexplored in greater depth during the COVID-19 pandemic. Furthermore, the mining results of marine pollution publications show the mitigation of plastic pollution in the marine environment remains the main content requires future research. Finally, this paper puts forward corresponding suggestions for the reference of researchers and practitioners to improve the global ability to respond to the challenges posed by the pandemic to the marine environment.