Estimates of particle hygroscopicity during the Southeastern Aerosol and Visibility Study

Aerosol water content was determined from relative humidity controlled optical particle counter (ASASP-X) size distribution measurements made during the Southeastern Aerosol and Visibility Study (SEAVS) in the Great Smoky Mountains National Park during summer 1995. Since the scattering response function of the ASASP-X is sensitive to particle refractive index, a technique for calibrating the ASASP-X for any real refractive index was developed. A new iterative process was employed to calculate water mass concentration and wet refractive index as functions of relative humidity. Experimental water mass concentrations were compared to theoretically predicted values assuming only ammonium sulfate compounds were hygroscopic. These comparisons agreed within experimental uncertainty. Estimates of particle hygroscopicity using a rural aerosol model of refractive index as a function of relative humidity demonstrated no significant differences from those made with daily varying refractive index estimates. Although aerosol size parameters were affected by the assumed chemical composition, forming ratios of these parameters nearly canceled these effects.     

Capacity of transportation and spread of COVID-19—an ironical fact for developed countries

Environmental Science and Pollution Research - The widespread epidemic of the COVID-19 in developed countries such as Europe and the USA has sparked many speculations. What factors caused the rapid...     

Land cover composition determinants in the Uckermark (NE Germany) over a 220-year period

There is broad consensus that land use/cover has changed in central Europe over millennia. However, few studies have addressed the roles of the anthropogenic (socio-economic) and natural (biophysical) factors driving these changes over shorter periods (e.g., 100 years). In this study, we analyse the determinants of land cover composition at three discrete time periods (c. 1780, 1890, and 2000). We hypothesise that different anthropogenic and natural factors are the determinants of the main land cover types (arable fields, grasslands, and forests) and that the effects of natural and anthropogenic factors on the main land cover types differ among landscapes with highly dynamic and more stable forest-open land distributions. The study was carried out in the Uckermark region located in northeastern Germany. We compiled data on natural and anthropogenic factors (e.g. forest cover and number of inhabitants) of 65 municipalities in four landscape sections of equal size (10 × 10 km). Landscape sections were selected to reflect different dynamics (high/low) in conversion from forest to arable fields or grasslands and vice versa from 1780 to 2000. Averaged linear mixed-effect models explained between 7.5 and 81.2 % of the variance. The unique effect of anthropogenic factors varied from 2.1 to 18.7 % and that of natural factors varied from 0.2 to 43.4 %. In four of six models that included both types of factors, the natural factors were more influential than the anthropogenic factors. Except in three cases, anthropogenic and natural factors showed opposite effects on land cover types in more dynamic and more stable windows. Though the Uckermark region has been influenced by human activity for thousands of years, natural factors were a major determinant of land cover composition during all time periods, whereas anthropogenic factors became more important only during the latest time period under investigation.     

Recognize fish as food in policy discourse and development funding

The international development community is off-track from meeting targets for alleviating global malnutrition. Meanwhile, there is growing consensus across scientific disciplines that fish plays a crucial role in food and nutrition security. However, this ‘fish as food’ perspective has yet to translate into policy and development funding priorities. We argue that the traditional framing of fish as a natural resource emphasizes economic development and biodiversity conservation objectives, whereas situating fish within a food systems perspective can lead to innovative policies and investments that promote nutrition-sensitive and socially equitable capture fisheries and aquaculture. This paper highlights four pillars of research needs and policy directions toward this end. Ultimately, recognizing and working to enhance the role of fish in alleviating hunger and malnutrition can provide an additional long-term development incentive, beyond revenue generation and biodiversity conservation, for governments, international development organizations, and society more broadly to invest in the sustainability of capture fisheries and aquaculture.Electronic supplementary materialThe online version of this article (10.1007/s13280-020-01451-4) contains supplementary material, which is available to authorized users.     

Sustainable Aquaculture: Are We Getting There? Ethical Perspectives on Salmon Farming

Aquaculture is the fastest growing animal producing sector in the world and is expected to play an important role in global food supply. Along with this growth, concerns have been raised about the environmental effects of escapees and pollution, fish welfare, and consumer health as well as the use of marine resources for producing fish feed. In this paper we present some of the major challenges salmon farming is facing today. We discuss issues of relevance to how to ensure sustainability, by focusing on animal production systems, breeding approaches, sources for feed ingredients, and genetic engineering strategies. Other crucial issues such as animal welfare, environmental quality, and ethics are elaborated with regard to relevance for the sustainability of aquaculture. Additionally, we comment on socio-economic distributive implications by intellectual property rights (IPR) strategies on access to genetic material and traceability. To improve sustainability of salmon farming we suggest that there is a need for new approaches to guide research, for identification of ethical issues, and for engaging stakeholders in resolving these challenges.     

Increased germination of diverse crop-wild hybrid sunflower seeds.

Gene flow from crop fields to wild populations produces hybrids that often differ from their wild counterparts in growth form, phenology, and life history characteristics. Germination and dormancy dynamics have a strong influence on population persistence, competitive dynamics, and ultimately, plant fitness. They may also play a role in modifying crop gene introgression, which has been of primary interest since the release of transgenic crops. We investigated how seed germination and dormancy were affected by sunflower crop wild hybridization in both laboratory and field experiments. Hybridization increased seed germination and decreased dormancy. Of the nine wild populations we assayed, most of their hybrids had higher germination than the wilds of the same population. However, absolute germination levels varied by population and testing environment. Hybrids produced by three different crop lines differed in germination, and their germination rankings shifted across populations. Increased germination in hybrids could accelerate crop gene introgression, provided that hybrids germinate in an appropriate period. Differences in relative germination of wild and hybrid seed indicated that the effect of germination on introgression will likely vary by population due, in part, to initial levels of dormancy in the population. Therefore, the implications of gene flow from crops with novel characteristics or from transgenic crops will also vary by population.     

INTERNATIONAL MANAGEMENT OF THE RIO GRANDE BASIN THE UNITED STATES AND MEXICO1

ABSTRACT. Despite radical differences in water laws, water management agencies, approaches to water planning, and financial resources, Mexico and the United States forged a common program to manage water and related land on the Rio Grande. Actions of Rio Grande Commissions related to stream gaging, boundary definition, and multiple-purpose construction projects are among the more successful international water-management efforts in the world. Cost-sharing arrangements promoted rapid completing of international works. However, joint action accomplished only part of expectations. International developments were competitive rather than complementary until basin water appropriation was virtually complete. Moreover, Commissions were not empowered to consider long-range competitive water needs, or regional water requirements, throughout the basin. International groundwater use coordination does not exist. International structures produce less than anticipated benefits. Hydroelectric generators are financial liabilities, irrigated acreage exceeds dependable streamflow, and soil salinization is experienced. Unanticipated environmental changes occurred in every major program. The Rio Grande experience points to the need for society to specify goals to which the use of water should contribute and to specify priorities for water use among different sectors of river basins and various segments of society.     

Climate and air quality-driven scenarios of ozone and aerosol precursor abatement

In addition to causing domestic and regional environmental effects, many air pollutants contribute to radiative forcing (RF) of the climate system. However, climate effects are not considered when cost-effective abatement targets for these pollutants are established, nor are they included in current international climate agreements. We construct air pollution abatement scenarios in 2030 which target cost-effective reductions in RF in the EU, USA, and China and compare these to abatement scenarios which instead target regional ozone effects and particulate matter concentrations. Our analysis covers emissions of PM (fine, black carbon and organic carbon), SO₂, NO_x, CH₄, VOCs, and CO. We find that the effect synergies are strong for PM/BC, VOC, CO and CH₄. While an air quality strategy targeted at reducing ozone will also reduce RF, this will not be the case for a strategy targeting particulate matter. Abatement in China dominates RF reduction, but there are cheap abatement options also available in the EU and USA. The justification for international cooperation on air quality issues is underlined when the co-benefits of reduced RF are considered. Some species, most importantly SO₂, contribute a negative forcing on climate. We suggest that given current knowledge, NO_x and SO₂ should be ignored in RF-targeted abatement policies.     

Health benefits from reducing indoor air pollution from household solid fuel use in China--three abatement scenarios

According to the World Health Organization (WHO), indoor air pollution (IAP) from the use of solid fuels in households in the developing world is responsible for more than 1.6 million premature deaths each year, whereof 0.42 million occur in China alone. We argue that the methodology applied by WHO--the so-called fuel-based approach--underestimates the health effects, and suggest an alternative method. Combining exposure-response functions and current mortality and morbidity rates, we estimate the burden of disease of IAP in China and the impacts of three abatement scenarios. Using linear exposure-response functions, we find that 3.5 [0.8-14.7 95% CI] million people die prematurely due to IAP in China each year. The central estimate constitutes 47% of all deaths in China. We find that modest changes in the use of cooking fuels in rural households might have a large health impact, reducing annual mortality by 0.63 [0.1-3. 2 95% CI] million. If the indoor air quality (IAQ) standard set by the Chinese government (150 microg PM(10)/m(3)) was met in all households, we estimate that 0.9 [0.2-4.8] million premature deaths would be avoided in urban areas and 2.8 [0.7-12.4] million in rural areas. However, in urban areas this would require improvements to the outdoor air quality in addition to a complete fuel switch to clean fuels in households. We estimate that a fuel switch in urban China could prevent 0.7 [0.2-4.8] million premature deaths. The methodology for exposure assessment applied here is probably more realistic than the fuel-based approach; however, the use of linear exposure-response relationships most likely tends to overestimate the effects. The discrepancies between our results and the WHO estimates is probably also explained by our use of "all-cause mortality" which includes important causes of death like cardiovascular diseases, conditions known to be closely associated with exposure to particulate pollution, whereas the WHO estimate is limited to respiratory diseases.