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Abstract Regulations, definitions, and calculations related to emissions of Volatile Organic Compounds (VOC) from paints used for horizontal road markings (traffic paints) in North America and in European Union are different, which frequently makes simple comparisons impossible. To illustrate the dissimilarities, solvent packages of various exemplary paints that meet several normative requirements were compared for the nominal emissions according to different calculation procedures. For a unified assessment, volatile portions of the paints were evaluated based on Ozone Formation Potential (OFP). The analysis revealed that similar nominal VOC contents can lead to vastly different OFP, in an extreme case six times higher. Incongruously high OFP, which was calculated for emissions in Southern California despite strict limits can thus be explained. The provided calculations can be used by road administrators as a tool to demand materials with lowest environmental impact, by environmental researchers to pinpoint irregularities between declared and measured discharges, and can assist formulating chemists in selection of raw materials to prepare environmentally friendly road marking paints. Graphical abstract Image 1 [ABSTRACT FROM AUTHOR]

Ammonia (NH 3 ) emissions from agriculture to the atmosphere, along with emissions of other pollutants from a variety of sources, are of concern to agriculture worldwide. National emissions from agricultural sources in Canada are linked to domestic consumption and export demand for agricultural products. The onus to limit emissions is often directed to the producers, but the marketplace and consumer are also responsible for the environmental impact of their choices. This objective of this study was to quantitatively link agricultural NH 3 emissions to per person consumption of food and protein and to agricultural exports from Canada. There are substantial differences in the NH 3 emissions per unit consumed protein among the various food types. As a result, shifts in the Canadian diet have had a large impact on relative per person NH 3 emissions. From 1981 to 2006, the total per person protein intake in the Canadian diet increased about 5%, but NH 3 emission related to that diet decreased 20%. This is largely related to consumption of less beef, which has a high emission per unit of meat or protein, and more poultry and cereals which have much lower emissions. Although these changes in diet were not because of environmental concerns by the consumers, they had substantial effects on national-level emissions. These consumer driven effects may well exceed the possible effects of best management practices intended to address NH 3 emissions at the producer level. Note that the Canadian population has increased 50% from 1981 to 2006 and meat and egg exports increased 570%, so that total emissions from food production in Canada have increased. Our results imply there will be further effects on national NH 3 emissions because of dietary and export drivers that are generally outside the scope of agro-environmental policy. [ABSTRACT FROM AUTHOR]

Abstract: The uncertain, future development of emissions of short-lived trace gases and aerosols forms a key factor for future air quality and climate forcing. The Representative Concentration Pathways (RCPs) only explore part of this range as they all assume that worldwide ambitious air pollution control policies will be implemented. In this study, we explore how different assumptions on future air pollution policy and climate policy lead to different concentrations of air pollutants for a set of RCP-like scenarios developed using the IMAGE model. These scenarios combine low and high air pollution variants of the scenarios with radiative forcing targets in 2100 of 2.6 W m−2 and 6.0 W m−2. Simulations using the global atmospheric chemistry and transport model TM5 for the present-day climate show that both climate mitigation and air pollution control policies have large-scale effects on pollutant concentrations, often of similar magnitude. If no further air pollution policies would be implemented, pollution levels could be considerably higher than in the RCPs, especially in Asia. Air pollution control measures could significantly reduce the warming by tropospheric ozone and black carbon and the cooling by sulphate by 2020, and in the longer term contribute to enhanced warming by methane. These effects tend to cancel each other on a global scale. According to our estimates the effect of the worldwide implementation of air pollution control measures on the total global mean direct radiative forcing in 2050 is +0.09 W m−2 in the 6.0 W m−2 scenario and −0.16 W m−2 in the 2.6 W m−2 scenario. [Copyright &y& Elsevier]

Abstract: China's air pollution control policies during the 12th Five Year Plan (2011–2015) are characterized by the targets of 10% nitrogen oxides (NO x ) reduction and 8% sulfur dioxide (SO2) reduction from the 2010 levels. In this study, the Community Multi-scale Air Quality (CMAQ) modeling system was used to evaluate the impact of only SO2, only NO x , and joint SO2/NO x control measures on particulate matter pollution, the greatest concern for urban air quality in China. Four emission scenarios were developed for 2015, including a business-as-usual scenario, a reference NO x control scenario based on the governmental plan, an accelerated NO x control technology scenario, and a scenario assuming joint controls of NO x and SO2 based on the governmental plan. Under the planned NO x control measures, the annual mean concentrations of particulate matter less than or equal to 2.5 μm (PM2.5) decline by 1.5–6 μg m−3, i.e. 1.6%–8.5%, in the majority of eastern China. The largest reduction occurs in the middle reach of the Yangtze River. Under accelerated NO x control measures, the annual average PM2.5 concentration reductions (compared with the business-as-usual scenario) in eastern China are 65% higher than the reductions under planned control measures. The unusual increase of PM2.5 concentrations in the North China Plain and the Yangtze River Delta during January after the reductions of NO x emissions was an integrated effect of excessive NO x , the ammonia-rich inorganic aerosol chemistry, and the non-methane volatile organic compounds (NMVOC) sensitive photochemical regime. Under the joint controls of NO x and SO2, the annual mean PM2.5 concentrations decline over 3 μg m−3, i.e. 3.2%–13%, in the majority of eastern China, and some areas in the middle reach of the Yangtze River have reductions as large as 6–8.3 μg m−3, i.e. 5.0%–13%. The average PM2.5 concentration reductions in eastern China are 1.20 μg m−3, 3.14 μg m−3, 3.57 μg m−3, 4.22 μg m−3 in January, May, August, and November, respectively. The corresponding declining rates are 2.3%, 12.2%, 14.3%, and 8.1%, respectively. More stringent policies should be implemented in winter to reduce the heavy pollution periods. The annual average PM2.5 concentration reductions in three major city clusters are comparable with the average reductions of eastern China. Stringent regional control policies are required for the significant improvement of particulate air quality in major city clusters. [Copyright &y& Elsevier]

Abstract: The air quality impacts of aviation are becoming increasingly important given their impact on human health and the projected growth of aviation. In the United States, the government has set targets to manage and reduce the environmental impacts of aviation. In an environmental policy assessment context it is often necessary to rapidly evaluate many possible scenarios, and quantification of uncertainty is important. This makes direct application of comprehensive air quality models such as the Community Multiscale Air Quality (CMAQ) modeling system impractical due to computational cost. Here we develop a response surface model (RSM) – a form of rapid surrogate model – of the impact of aviation emissions on air quality in the United States. We develop an RSM design space and populate it with results from 46 CMAQ simulations, and perform cross-validation of the resultant RSM. The RSM models present-day as well as future impacts amid changing population and non-aviation emissions sources. This enables rapid estimates of the (particulate matter) air quality and human health impacts of aviation emissions scenarios. Cross-couplings between precursor gaseous emissions and PM2.5 species are found, consistent with competition for atmospheric ammonia. We apply the RSM to quantify the human health benefits of emissions reductions in 2018. Using the RSM we estimate that in 2005, aviation landing and takeoff emissions cause ∼195 [90% CI: 80–340] early deaths, while the same emissions cause ∼350 [90% CI: 145–610] mortalities in 2018. An emissions tradespace between aviation NO x and SO x emissions is constructed. It is found that with fleet-wide desulfurization of jet fuel, a 35% reduction in aviation NO x emissions would result in maintaining the same level of aviation-attributable early deaths in 2018 relative to 2005 levels, while an 80% reduction in NO x emissions would half aviation-attributable early deaths. [Copyright &y& Elsevier]

Abstract: For policy-making, human health risks of fine particulate m(PM2.5) are commonly assessed by comparing environmental concentrations with reference values, which does not necessarily reflect the impact on health in a population. The goal of this study was to compare health impacts in the Moerdijk area, The Netherlands resulting from local emissions of PM2.5 from industry and traffic in a case study using the risk advancement period (RAP) of mortality. The application of the RAP methodology on the local scale is a promising technique to quantify potential health impacts for communication purposes. The risk advancement period of mortality is the time period by which the mortality risk is advanced among exposed individuals conditional on survival at a baseline age. The RAP showed that road traffic was the most important local emission source that affects human health in the study area, whereas the estimated health impact from industry was a factor of 3 lower. PM2.5 due to highway-traffic was the largest contributor to the health impact of road traffic. This finding is in contrast with the risk perception in this area. [Copyright &y& Elsevier]

Abstract: Monte Carlo sampling of pre-specified parameter ranges has been used to replace single ‘best estimate’ Photochemical Trajectory Model runs with 9006 ‘acceptable’ model runs that were each consistent with the observations of elevated O3 during July 2006 at a rural location in southern England. These acceptable parameter sets were then used for probabilistic evaluation of policy relevant photochemical oxidant control strategies, based on 30% reductions in VOC and NO x precursor emissions and the geographic locations where the emission reductions were carried out. Indicator species ratios were used to complete a diagnostic evaluation of model performance. The chemical mechanism employed in the base case model was replaced with four other mechanisms from the literature. Probabilistic uncertainty analysis showed that the results of the policy-relevant scenarios showed little or no sensitivity to chemical mechanism choice. A large degree of error compensation could be achieved through the selection of acceptable parameter sets and this hid the differences between the five chemical mechanisms studied. [Copyright &y& Elsevier]

Abstract: The potential adverse human health impacts of emissions from UK airports have become a significant issue of public concern. We produce an inventory of UK airport emissions – including emissions from aircraft landing and takeoff operations, aircraft auxiliary power units (APUs) and ground support equipment (GSE) – with quantified uncertainty. Emissions due to more than 95% of UK passenger enplanements are accounted for. We apply a multi-scale air quality modelling approach to assess the air quality impacts of UK airports. Using a concentration-response function we estimate that 110 (90% CI: 72–160) early deaths occur in the UK each year (based on 2005 data) due to UK airport emissions. We estimate that up to 65% of the health impacts of UK airports could be mitigated by desulphurising jet fuel, electrifying GSE, avoiding use of APUs and use of single engine taxiing. Two plans for the expansion of UK airport capacity are examined – expansion of London Heathrow and new hub airport in the Thames Estuary. Even if capacity is constrained, we find that the health impacts of UK airports still increases by 170% in 2030 due to an increasing and aging population, increasing emissions, and a changing atmosphere. We estimate that if Heathrow were to be expanded as per previous UK Government plans, UK-wide health impacts in 2030 would increase by 4% relative to the 2030 constrained case, but this increase could become a 48% reduction if emissions mitigation measures were employed. We calculate that 24% of UK-wide aviation-attributable early deaths could be avoided in 2030 if Heathrow were replaced by a new airport in Thames Estuary because the location is downwind of London, where this reduction occurs notwithstanding the increase in aircraft emissions. A Thames hub airport would (isolated from knock-on effects at other airports) cause 60–70% fewer early deaths than an expanded Heathrow, or 55–63% fewer early deaths than an unexpanded Heathrow. Finally, replacing Heathrow by a Thames Estuary airport combined with emissions mitigation measures would reduce UK-wide aviation-attributable early deaths by 56% in 2030 while increasing aircraft movements, which would represent aviation causing about the same level of adverse health impacts as today in absolute terms. We note that because aviation emissions are included in the EU Emissions Trading Scheme, all options are CO2-neutral in terms of direct emissions (but not climate-neutral). [Copyright &y& Elsevier]

Abstract: To reduce air pollution levels in Santiago, Chile on days when the weather is expected to create poor ventilation conditions and increased air pollutant concentrations, the responsible authorities impose temporary restrictions on motor vehicles and certain industrial activities. We estimate the impact of these restrictions on the city''s air quality using data collected by a network of monitoring stations. The estimates show that the restrictions do reduce the average concentrations of coarse and fine particulate matter, carbon monoxide and nitrogen oxide (both gases are emitted mainly by vehicles). However, no significant changes were found in the sulfur dioxide concentrations, which are primarily the result of industrial processes. [Copyright &y& Elsevier]

Abstract: Concentrations of 13 organic source markers (10 polycyclic aromatic hydrocarbons and 3 hopanes) are reported from time-integrated samples (24-h and sub-daily) collected near a highway in Las Vegas, NV. Sample selection for assessing source impacts from the roadway was completed using the wind regression model Air Pollution Transport to Receptor model (EPA APTR 1.0). The model uses a kernel smoothing method for estimating source sectors (sector apportionment) of chemicals across wind speeds and wind directions. The model was applied using semi-continuous (5-min averaging time) pollutant data (black carbon (BC), CO, NO2, and NOx) and meteorological data. Using simple screening criteria to identify source impacts (>30% sector apportionment from the roadway and errors in the estimated sector apportionment <30%), sector apportionment results were consistent with organic source marker concentrations representative of motor vehicle exhaust (e.g., benzo(g,h,i)perylene and hopane). Results demonstrated the use of APTR to identify source-impacted time intervals when compared with filter samples analyzed for organic source markers. [Copyright &y& Elsevier]

The ammonium-to-sulfate ratio ([NH4+]/[SO42-]) and the strong acidity have been generally used as parameters to describe the acidic nature of atmospheric aerosols. However, both parameters do not provide the in situ acidic characteristics of atmospheric aerosols, which are more relevant to the reactivity and the environmental impacts of the aerosols. In this study, the in situ free acid concentrations and the in situ pH of aerosols are investigated to understand the acidic characteristics of atmospheric aerosols in Hong Kong (HK). Over 182 datasets on 24 h Respirable Suspended Particles (RSP) samples collected in 2001 from seven air-quality-monitoring sites run by the Hong Kong Environmental Protection Department are analyzed. Simulations using the Aerosol Inorganic Model (AIM2) reveal that the in situ acidity, i.e., the free acid concentration ([H+]free), is only a minor fraction (∼23%) of the estimated strong acidity in the fine particles because of the presence of bisulfate ions. The acidity characteristics of fine particles are a function of mainly RH and ammonium to sulfate ratio. The in situ free acid concentration, the normalized water content ([H2O]AIM2/[SO42-]), and the dissociation of bisulfate to free acid in the aerosols decrease as the [NH4+]/[SO42-] ratio increases and the Relative Humidity (RH) decreases. The acidic fine mode particles have average molar [NH4+]/[SO42-] ratio of 1.42, strong acidity of 51 nmol m-3, in situ acidity of 11 nmol m-3, and in situ pH of 0.25 on average. Our findings suggest that even the more neutralized ([NH4+]/[SO42-] >1.5) particles, such as those found when HK is under the influence of continental air masses from the Chinese mainland, can have high in situ acidity and low pH when the RH is low. This study calls for more investigation of the acidity of aerosols in HK, incorporating the concepts of in situ acidity and pH. [Copyright &y& Elsevier]