Impact of the Volkswagen emissions control defeat device on US public health

The US Environmental Protection Agency (EPA) has alleged that Volkswagen Group of America (VW) violated the Clean Air Act (CAA) by developing and installing emissions control system 'defeat devices' (software) in model year 2009–2015 vehicles with 2.0 litre diesel engines. VW has admitted the inclusion of defeat devices. On-road emissions testing suggests that in-use NO[subscript x] emissions for these vehicles are a factor of 10 to 40 above the EPA standard. In this paper we quantify the human health impacts and associated costs of the excess emissions. We propagate uncertainties throughout the analysis. A distribution function for excess emissions is estimated based on available in-use NO[subscript x] emissions measurements. We then use vehicle sales data and the STEP vehicle fleet model to estimate vehicle distance traveled per year for the fleet. The excess NO[subscript x] emissions are allocated on a 50 km grid using an EPA estimate of the light duty diesel vehicle NO[subscript x] emissions distribution. We apply a GEOS-Chem adjoint-based rapid air pollution exposure model to produce estimates of particulate matter and ozone exposure due to the spatially resolved excess NO[subscript x] emissions. A set of concentration-response functions is applied to estimate mortality and morbidity outcomes. Integrated over the sales period (2008–2015) we estimate that the excess emissions will cause 59 (95% CI: 10 to 150) early deaths in the US. When monetizing premature mortality using EPA-recommended data, we find a social cost of ~$450m over the sales period. For the current fleet, we estimate that a return to compliance for all affected vehicles by the end of 2016 will avert ~130 early deaths and avoid ~$840m in social costs compared to a counterfactual case without recall

Air pollution and early deaths in the United States : attribution of PM₂.₅ exposure to emissions species, time, location and sector

Thesis: S.M., Massachusetts Institute of Technology, Department of Aeronautics and Astronautics, 2014.Cataloged from PDF version of thesis.Includes bibliographical references (pages 35-37).Combustion emissions constitute the largest source of anthropogenic emissions in the US. They lead to the degradation of air quality and human health, by contributing to the formation of fine particulate matter (PM2 .5 ), which is harmful to human health. Previous work computed the population PM2 .5 exposure and number of early deaths caused by emissions from six major sectors: electric power generation, industry, commercial and residential activities, road transportation, marine transportation and rail transportation. In the present work we go beyond aggregate sectors and now attribute exposure and early deaths to sectors, emissions species, time of emission, and location of emission. This enables determination of the emissions reductions that would have the greatest benefit by sectors, species, time and location. We apply a long-term adjoint sensitivity analysis with population exposure to PM2 .5 in the contiguous US as the objective function, and calculate the four dimensional sensitivities (time and space) of PM2 .5 exposure with respect to each emissions species. Epidemiological evidence is used to relate increased population exposure to premature mortalities. This is the first regional application of the adjoint sensitivity analysis method to characterize long-term air pollution exposure. (A global scale application has been undertaken related to intercontinental pollution.) We find that for the electric power generation sector 75% of the attributable PM2 .5 exposure is due to SO2 emissions, and 80% of the annual impacts are attributed to emissions from April to September. This suggests that burning of low sulfur coal has greatest benefit in the summer. In the road transportation sector, 29% of PM2 .5 exposure is due to NO, emissions and 33% from ammonia (NH3), which is a result of emissions after-treatment technologies. We estimate that the benefit of reducing NH3 emissions from road transportation is ~20 times that of NOx per unit mass. 75% of the road transportation ammonia impacts occur during the months October to March. We rank the states based on their contribution to the overall combustion emissions-attributable PM2 .5 exposure in the US, and calculate that California contributes 12%, Pennsylvania 7% and Ohio 5.8%. We publicly release the sensitivity matrices computed, noting their potential use as a rapid air quality policy assessment tool.by Irene Constantina Dedoussi.S.M

Adjoint sensitivity analysis of the atmospheric impacts of combustion emissions

Thesis: Ph. D., Massachusetts Institute of Technology, Department of Aeronautics and Astronautics, 2018.Cataloged from PDF version of thesis.Includes bibliographical references (pages 127-149).Combustion emissions impact the environment through chemical and transport processes that span varying temporal and spatial scales. Numerical simulation of the effects of combustion emissions and potential corresponding mitigation approaches is computationally expensive. Atmospheric adjoint modeling enables the calculation of receptor-oriented sensitivities of environmental metrics of interest to emissions, overcoming the numerical cost of conventional modeling. This thesis applies and further develops an existing adjoint of a chemistry-transport model to perform three evaluations, where the high number of inputs (due to the nature of the problem or the associated uncertainty) prevented comprehensive assessment in the past. First, this thesis quantifies the pollution exchange between the US states for seven major anthropogenic combustion emissions sectors: electric power generation, industry, commercial/residential, aviation, as well as road, marine, and rail transportation. This thesis presents the state-level fine particulate matter (PM₂.₅) early death impacts of combustion emissions in the US for 2005, 2011 and 2018 (forecast), and how these are driven by sector, chemical species, and location of emission. Results indicate major shifts in the chemical species and sectors that cause most early deaths, and opportunities for further improving air quality in the US. Second, this thesis quantifies how changes in emissions impact the marginal atmospheric PM₂.₅ response to emissions perturbations. State-level annual adjoint sensitivities of PM₂.₅ population exposure to precursor emissions are compared for the years of 2006 and 2011, and correlated with the magnitude of emissions reduction and the background ammonia mixing ratio. Third, this thesis presents the development and evaluation of the discrete adjoint of the GEOS-Chem unified tropospheric-stratospheric chemistry extension (UCX), which enables the calculation of stratospheric sensitivities and the examination of the entire design space of high altitude emissions impacts. To illustrate its potential, sensitivities of stratospheric ozone to precursor species are calculated. This development expands the span of atmospheric chemistry-transport questions (including inversions) that this open-source model can be used to answer. The assessments performed in this thesis span spatial scales from the regional to the global and demonstrate the ability of this approach to provide information on both bottom-up and top-down mitigation approaches.by Irene Constantina Dedoussi.Ph. D

Comparisons of simple and complex methods for quantifying exposure to individual point source air pollution emissions

© 2020, The Author(s), under exclusive licence to Springer Nature America, Inc. Expanded use of reduced complexity approaches in epidemiology and environmental justice investigations motivates detailed evaluation of these modeling approaches. Chemical transport models (CTMs) remain the most complete representation of atmospheric processes but are limited in applications that require large numbers of runs, such as those that evaluate individual impacts from large numbers of sources. This limitation motivates comparisons between modern CTM-derived techniques and intentionally simpler alternatives. We model population-weighted PM2.5 source impacts from each of greater than 1100 coal power plants operating in the United States in 2006 and 2011 using three approaches: (1) adjoint PM2.5 sensitivities calculated by the GEOS-Chem CTM; (2) a wind field-based Lagrangian model called HyADS; and (3) a simple calculation based on emissions and inverse source-receptor distance. Annual individual power plants’ nationwide population-weighted PM2.5 source impacts calculated by HyADS and the inverse distance approach have normalized mean errors between 20 and 28% and root mean square error ranges between 0.0003 and 0.0005 µg m−3 compared with adjoint sensitivities. Reduced complexity approaches are most similar to the GEOS-Chem adjoint sensitivities nearby and downwind of sources, with degrading performance farther from and upwind of sources particularly when wind fields are not accounted for.NIH (Grants R01ES026217, K99ES027023, EPA 83587201, and HEI 4953

Public Health Impacts of Excess NO[subscript x] Emissions from Volkswagen Diesel Passenger Vehicles in Germany

In September 2015, the Volkswagen Group (VW) admitted the use of 'defeat devices' designed to lower emissions measured during VW vehicle testing for regulatory purposes. Globally, 11 million cars sold between 2008 and 2015 are affected, including about 2.6 million in Germany. On-road emissions tests have yielded mean on-road NO[subscript x] emissions for these cars of 0.85 g km⁻¹, over four times the applicable European limit of 0.18 g km⁻¹. This study estimates the human health impacts and costs associated with excess emissions from VW cars driven in Germany. A distribution of on-road emissions factors is derived from existing measurements and combined with sales data and a vehicle fleet model to estimate total excess NO[subscript x] emissions. These emissions are distributed on a 25 by 28 km grid covering Europe, using the German Federal Environmental Protection Agency's (UBA) estimate of the spatial distribution of NO[subscript x] emissions from passenger cars in Germany. We use the GEOS-Chem chemistry-transport model to predict the corresponding increase in population exposure to fine particulate matter and ozone in the European Union, Switzerland, and Norway, and a set of concentration-response functions to estimate mortality outcomes in terms of early deaths and of life-years lost. Integrated over the sales period (2008–2015), we estimate median mortality impacts from VW excess emissions in Germany to be 1200 premature deaths in Europe, corresponding to 13 000 life-years lost and 1.9 billion EUR in costs associated with life-years lost. Approximately 60% of mortality costs occur outside Germany. For the current fleet, we estimate that if on-road emissions for all affected VW vehicles in Germany are reduced to the applicable European emission standard by the end of 2017, this would avert 29 000 life-years lost and 4.1 billion 2015 EUR in health costs (median estimates) relative to a counterfactual case with no recall

Public health impacts of excess NOx emissions from Volkswagen diesel passenger vehicles in Germany

In September 2015, the Volkswagen Group (VW) admitted the use of 'defeat devices' designed to lower emissions measured during VW vehicle testing for regulatory purposes. Globally, 11 million cars sold between 2008 and 2015 are affected, including about 2.6 million in Germany. On-road emissions tests have yielded mean on-road NO[subscript x] emissions for these cars of 0.85 g km[superscript −1], over four times the applicable European limit of 0.18 g km[superscript −1]. This study estimates the human health impacts and costs associated with excess emissions from VW cars driven in Germany. A distribution of on-road emissions factors is derived from existing measurements and combined with sales data and a vehicle fleet model to estimate total excess NO[subscript x] emissions. These emissions are distributed on a 25 by 28 km grid covering Europe, using the German Federal Environmental Protection Agency's (UBA) estimate of the spatial distribution of NO[subscript x] emissions from passenger cars in Germany. We use the GEOS-Chem chemistry-transport model to predict the corresponding increase in population exposure to fine particulate matter and ozone in the European Union, Switzerland, and Norway, and a set of concentration-response functions to estimate mortality outcomes in terms of early deaths and of life-years lost. Integrated over the sales period (2008–2015), we estimate median mortality impacts from VW excess emissions in Germany to be 1200 premature deaths in Europe, corresponding to 13 000 life-years lost and 1.9 billion EUR in costs associated with life-years lost. Approximately 60% of mortality costs occur outside Germany. For the current fleet, we estimate that if on-road emissions for all affected VW vehicles in Germany are reduced to the applicable European emission standard by the end of 2017, this would avert 29 000 life-years lost and 4.1 billion 2015 EUR in health costs (median estimates) relative to a counterfactual case with no recall.Germany. Umweltbundesamt (UBA