What do you think caused your ALS? An analysis of the CDC national amyotrophic lateral sclerosis patient registry qualitative risk factor data using artificial intelligence and qualitative methodology.

Objective: Amyotrophic lateral sclerosis (ALS) is an incurable, progressive neurodegenerative disease with a significant health burden and poorly understood etiology. This analysis assessed the narrative responses from 3,061 participants in the Centers for Disease Control and Prevention's National ALS Registry who answered the question, "What do you think caused your ALS?" Methods: Data analysis used qualitative methods and artificial intelligence (AI) using natural language processing (NLP), specifically, Bidirectional Encoder Representations from Transformers (BERT) to explore responses regarding participants' perceptions of the cause of their disease. Results: Both qualitative and AI analysis methods revealed several, often aligned themes, which pointed to perceived causes including genetic, environmental, and military exposures. However, the qualitative analysis revealed detailed themes and subthemes, providing a more comprehensive understanding of participants' perceptions. Although there were areas of alignment between AI and qualitative analysis, AI's broader categories did not capture the nuances discovered using the more traditional, qualitative approach. The qualitative analysis also revealed that the potential causes of ALS were described within narratives that sometimes indicate self-blame and other maladaptive coping mechanisms. Conclusions: This analysis highlights the diverse range of factors that individuals with ALS consider as perceived causes for their disease. Understanding these perceptions can help clinicians to better support people living with ALS (PLWALS). The analysis highlights the benefits of using traditional qualitative methods to supplement or improve upon AI-based approaches. This rapidly evolving area of data science has the potential to remove barriers to accessing the rich narratives of people with lived experience.

A brief report on juvenile amyotrophic lateral sclerosis cases in the United States National ALS Registry: 2010-2018.

Juvenile ALS (jALS) is a rare form of ALS, defined as symptom onset before age 25. This report describes the demographic characteristics of confirmed and likely jALS cases in a large cohort of ALS patients ascertained in the National ALS Registry (Registry) from 2010 to 2018. Patients in the Registry must be at least 18 years of age. Of the 44 identified patients, 37.8% were diagnosed at age 24, were more likely to be nonwhite (54.5%), male (79.5%), and live in the Midwest or Northeast regions (54.5%) of the US. Some 68.9% of the jALS cases were received from federal administrative databases, and 16% came from the web portal only. Demographic characteristics for jALS cases in the Registry differed from previous publications examining ALS cases for all adults. More research is needed to better understand risk factors contributing to jALS, which could lead to earlier diagnosis and therapeutic interventions.

Prevalence of amyotrophic lateral sclerosis in the United States, 2018.

OBJECTIVE: To estimate prevalent ALS cases in the United States for calendar year 2018. METHODS: The National ALS Registry (Registry) compiled data from national administrative databases (from the Centers for Medicare and Medicaid Services, the Veterans Health Administration, and the Veterans Benefits Administration) and enrollment data voluntarily submitted through a web portal (www.cdc.gov/als). We used log-linear capture-recapture (CRC) model-based methodology to estimate the number of cases not ascertained by the Registry. RESULTS: The Registry identified 21,655 cases of ALS in 2018, with an age-adjusted prevalence of 6.6 per 100,000 U.S. population. When CRC methods were used, an estimated 29,824 cases were identified, for an adjusted prevalence of 9.1 per 100,000 U.S. population. The demographics of cases of ALS did not change from previous year's reports. ALS continues to impact Whites, males, and persons over 50 years of age more so than other comparison groups. The results from the present report suggest case ascertainment for the Registry has improved, with the estimate of missing prevalent cases decreasing from 44% in 2017 to 27% in in 2018. DISCUSSION: Consistent with previous estimates that used CRC, ALS prevalence in the United States is about 29,824 cases per year.

Comparing Amyotrophic lateral sclerosis (ALS) patient characteristics from the National ALS Registry and the Massachusetts ALS Registry, data through 2015.

OBJECTIVE: To compare, for completeness, ALS patients identified in the National ALS Registry (National Registry) from MA to those in the Massachusetts ALS Registry (MA Registry) through 2015. METHODS: Sensitivity analyses were conducted to determine the completeness among patients reported in both registries. Patients were matched on first and last name, month and year of birth, sex, as well as Soundex name matching. Demographics for matching and nonmatching ALS patients were also examined using bivariate analyses and logistic regression. RESULTS: There were 1,042 ALS patients in the MA Registry, and 642 patients matched (61.6%) in the National Registry. Sensitivity analyses found the National Registry had a sensitivity of 87.7% and specificity of 60%. For these matched patients, 522 (81.2%) came from Medicare. Of the 400 patients in the MA Registry not matched to the National Registry, 11.1% were nonwhite, compared to 6.0% in the matched group) (p = 0.0091) and 59.2% were diagnosed before age 60, compared to 28.6% in the matched group (p < 0.0001). Multivariate logistic regression analysis showed being an ALS case (p < 0.0001) and having an ALS diagnosis at age 60 or later (p < 0.0001) were associated with being more likely to match between the two registries. CONCLUSIONS: These findings show that ALS's non-notifiable condition status at the national level continues to pose a challenge in identifying all ALS patients. This analysis also showed missing cases at the state level even with a reporting statute. Additional strategies are needed for better patient-ascertainment to quantify all ALS patients in the U.S.

Assessment of Chemical Exposures Investigation After Fire at an Industrial Chemical Facility in Winnebago County, Illinois.

After a chemical fire, an investigation assessed health effects by using syndromic surveillance to monitor emergency department (ED) visits, a general health survey to assess the general public, and a first responders health survey to assess first responders. A total of four separate multivariable logistic regression models were developed to examine associations between reported exposure to smoke, dust, debris, or odor with any reported symptom in the general public. Syndromic surveillance identified areas with increased ED visits. Among general health survey respondents, 45.1% (911 out of 2,020) reported at least one symptom. Respondents reporting exposure to smoke, dust, debris, or odor had 4.5 (95% confidence interval (CI) [3.7, 5.5]), 4.6 (95% CI [3.6, 5.8]), 2.0 (95% CI [1.7, 2.5]), or 5.8 (95% CI [4.7, 7.3]) times the odds of reporting any symptom compared with respondents not reporting exposure to smoke, dust, debris, or odor, respectively. First responders commonly reported contact with material and being within 1 mi of the fire ≥5 hr; 10 out of 31 of first responders reported at least one symptom. There was high symptom burden reported after the fire. Results from our investigation might assist the directing of public health resources to effectively address immediate community needs and prepare for future incidents.

Prevalence of amyotrophic lateral sclerosis in the United States using established and novel methodologies, 2017.

Objective:To estimate the prevalence of amyotrophic lateral sclerosis (ALS) in the United States for 2017 using data from the National ALS Registry (Registry) as well as capture-recapture methodology to account for under-ascertainment. Established in 2010, the Registry collects and examines data on ALS patients in the US to better describe the epidemiology of ALS (i.e. risk factor exposures, demographics).Methods: The Registry compiled data from national administrative databases (from the Centers for Medicare and Medicaid Services, the Veterans Health Administration, and the Veterans Benefits Administration) and a voluntary enrollment data through a web portal (www.cdc.gov/als). To estimate the number of missing cases, capture-recapture methodology was utilized.Results: The Registry conservatively identified 17,800 adult persons (lower-bound estimate) who met the Registry definition of ALS for an age-adjusted prevalence of 5.5 per 100,000 US population. Using capture-recapture methodology, we obtained a "mean case count" of 24,821 ALS cases (prevalence of 7.7 per 100,000 U.S. population) and estimated the upper-bound estimate to be 31,843 cases (prevalence of 9.9 per 100,000 U.S. population). The pattern of patient characteristics (e.g. age, sex, and race/ethnicity) remained unchanged from previous Registry reports. Overall, ALS was most common among whites, males, and persons aged 60-69 years. The age groups with the lowest number of cases were persons aged 18-39 years. Males had a higher prevalence than females overall and across all data sources.Conclusions: Existing Registry methodology, along with capture-recapture methodology, are being used to better describe the epidemiology and demographics of ALS in the US.

Survival and epidemiology of amyotrophic lateral sclerosis (ALS) cases in the Chicago and Detroit metropolitan cohort: incident cases 2009-2011 and survival through 2018.

Amyotrophic lateral sclerosis (ALS) is a fatal, progressive neurodegenerative disorder. The National ALS Registry launched surveillance projects to understand the distribution of ALS in targeted geographic cohorts. OBJECTIVE: To describe the demographics, incidence, and survival of persons with ALS (PALS) identified in the Chicago and Detroit area population-based cohort. METHODS: Neurologists in the catchment area provided case reports for eligible ALS cases diagnosed and/or cared for from 1 January 2009 through 31 December 2011. Crude incidence rates were calculated for 2009-2011 and stratified by race and ethnicity. Using data from the National Death Index through 2018, we modeled the effect of patient covariates on mortality using the Cox proportional hazard regression. RESULTS: Of the 574 cases, 372 (64.8%) were diagnosed from 2009 to 2011. The combined crude incidence rates for 2009, 2010, and 2011 were 1.44, 1.53, and 1.73 cases per 100,000 person-years, respectively. Of the 486 subjects with complete survival data, 81% were deceased at the end of follow-up. Median survival time was 2.2 years, with 30% and 9% of subjects surviving past 5 and 10 years after diagnosis, respectively. Additionally, female PALS and PALS with longer time between symptom onset and diagnosis experienced longer survival. Nonwhites also experienced longer survival than Whites, except for those cases diagnosed in the younger age categories. CONCLUSION: Understanding the survival of ALS patients can aid in understanding variable prognostic factors, which can potentially extend survival and improve disease management.

Impact of the National Amyotrophic Lateral Sclerosis Registry: Analysis of Registry-funded Research.

OBJECTIVE: This research aims to examine the impact of the National Amyotrophic Lateral Sclerosis (ALS) Registry-funded research activities. METHODS: Registry-funded research and related publications were identified through the National ALS Registry website, the National Institutes of Health (NIH) Reporter website, and verified by Principal Investigators. Key study characteristics (e.g., study population, sample size) and key impact features (e.g., risk factors) were abstracted and recorded on study abstraction forms. Descriptive statistics were used to analyze the volume, productivity, and findings of the Registry-funded research. RESULTS: Since 2012, the National ALS Registry funded 21 research projects. Of these, 14 were through extramural research grants and included in the analysis. These studies are often related to environmental, medical conditions, and genetic risk factors. On average, the funded grants produced 1 to 2 publications which were cited 114 times by other researchers. The relative citation ratio averaged 1.81 with a weighted relative citation ratio of 16.28. These studies supported the identification and confirmation of candidate risk factors. Environmental and occupational risk factors typically related to heavy metal exposure (e.g., lead, mercury) and agricultural chemicals (e.g., pesticides, herbicides), and the occupations associated with exposure to these substances were most frequently explored. INTERPRETATION: The National ALS Registry is a multifaceted research platform, one component of which is funded research. This Registry-funded research fills an essential gap in the overall ALS scientific community as it is difficult to prevent and treat a disease without a deeper understanding of its causes.

Incidence of amyotrophic lateral sclerosis in the United States, 2014-2016.

Objective: To estimate the incidence of amyotrophic lateral sclerosis (ALS) in the United States for calendar years 2014-2016 using data from the National ALS Registry (Registry). The Registry collects data on ALS patients in the United States to better describe the epidemiology of ALS, examine risk factors such as environmental and occupational exposures, and characterize the demographics of those living with the disease. Methods: To identify adult incident cases of ALS, the Registry compiles data from three national administrative databases (maintained by the Centers for Medicare and Medicaid Services, the Veterans Health Administration, and the Veterans Benefits Administration). For cases that are not included in these databases, the Registry includes data collected from patients who voluntarily enroll via a secure web portal. Results: The Registry identified 5695 ALS cases in 2014; 6045 cases in 2015; and 4861 cases in 2016 for age-adjusted incidence rates of 1.7 (2014), 1.5 (2015), and 1.5 (2016) per 100,000 U.S. population, respectively. ALS was more common among whites, males, and persons aged 60-79 years. Conclusions: This is the first time administrative and self-reported databases have been used to describe the incidence of ALS for the United States resulting in a better estimate of disease demographics.

Case-control study in ALS using the National ALS Registry: lead and agricultural chemicals are potential risk factors.

Objective: To identify occupational risk factors for ALS using well-characterized participants with ALS (P-ALS), sibling controls (S-controls), and matched population controls (P-controls) within the National ALS Registry. We also compared oxidative stress (OS) biomarkers between groups. Methods: P-ALS were recruited over 4 years. Demographic, socioeconomic, and medical data were ascertained from medical records and structured interviews. P-ALS were followed prospectively for 2 years or until death, whichever came sooner. S-controls and age-, sex-, race/ethnicity-, and residential location-matched P-controls were recruited over 3 years. Occupational exposure to lead and agricultural chemicals (ACs) were assigned by an occupational hygienist, blinded to case status. OS biomarkers in urine were measured. Results: P-ALS (mean age 62.8 years; 63% males) resided across the United States. Demographic and socioeconomic variables did not differ among P-ALS, S-controls, and P-controls. P-ALS were more likely to report occupations with exposure to lead (adjusted OR (aOR)=2.3, 95% CI 1.1, 4.6) and ACs (aOR = 2.4, 95% CI 1.2, 4.6) compared to pooled controls. Among those with occupations with exposure to both lead and ACs, aOR was 7.2 (95% CI 2.0, 26.1). Urinary 8-oxo-dG was significantly elevated among P-ALS (11.07 ± 5.42 ng/mL) compared to S-controls, P-controls, or pooled controls (pooled 7.43 ± 5.42 ng/mL; p < 0.0001) but was not associated with occupational exposure to either lead or ACs. Conclusions: Findings reveal increased risk of ALS diagnosis among those with occupational exposure to lead and ACs and increased OS biomarkers among cases compared to controls. OS may be an important pathogenic mechanism in ALS.

Evaluation of the Completeness of ALS Case Ascertainment in the US National ALS Registry: Application of the Capture-Recapture Method.

INTRODUCTION: The Centers for Disease Control and Prevention (CDC) National Amyotrophic Lateral Sclerosis (ALS) Registry is the first national registry for a chronic neurologic disease in the USA and uses a combination of case-finding methods including administrative healthcare data and patient self-registration. METHODS: We applied capture-recapture methodology to estimate the completeness of the Registry for ascertaining patients with ALS for the first full year and the fourth year of the Registry (2011, 2014). The Registry uses the combination of two national administrative claims databases (Medicare and Veterans Affairs) with a self-register option at the registry portal. We conducted descriptive analyses of the demographic and clinical characteristics of the ALS cases identified by each of the sources and estimated the completeness of case ascertainment for each of the three ALS Registry sources individually, pairwise, and in all combinations. RESULTS: Case-finding completeness was 54% in 2011 and improved to 56% in 2014. A smaller proportion of ALS patients under age 65 were ascertained than those 65 or older, and ascertainment was also lower for nonwhite than white patients. The uncorrected ALS prevalence was 4.3/100,000 in 2011 (in 2014, 5.0/100,000), but after correction for underascertainment, annual prevalence in 2011 was 7.9/100,000 (95% CI: 7.6-8.2) (in 2014 was 8.9/100,000 [95% CI: 8.7-9.2]). DISCUSSION/CONCLUSION: Our findings indicate that administrative healthcare databases are a very efficient method for identifying the majority of ALS prevalent cases in the National ALS Registry and that the inclusion of a web registry portal for patients to self-register is important to ensure a more representative population for estimating ALS prevalence. Nonetheless, more than 40% of ALS cases were not ascertained by the Registry, with individuals younger than age 65 and people of color underrepresented. Recommendations are provided for additional methods that can be considered to improve the completeness of case ascertainment.

Recruitment of Patients With Amyotrophic Lateral Sclerosis for Clinical Trials and Epidemiological Studies: Descriptive Study of the National ALS Registry's Research Notification Mechanism.

BACKGROUND: Researchers face challenges in patient recruitment, especially for rare, fatal diseases such as amyotrophic lateral sclerosis (ALS). These challenges include obtaining sufficient statistical power as well as meeting eligibility requirements such as age, sex, and study proximity. Similarly, persons with ALS (PALS) face difficulty finding and enrolling in research studies for which they are eligible. OBJECTIVE: The aim of this study was to describe how the federal Agency for Toxic Substances and Disease Registry's (ATSDR) National ALS Registry is linking PALS to scientists who are conducting research, clinical trials, and epidemiological studies. METHODS: Through the Registry's online research notification mechanism (RNM), PALS can elect to be notified about new research opportunities. This mechanism allows researchers to upload a standardized application outlining their study design and objectives, and proof of Institutional Review Board approval. If the application is approved, ATSDR queries the Registry for PALS meeting the study's specific eligibility criteria, and then distributes the researcher's study material and contact information to PALS via email. PALS then need to contact the researcher directly to take part in any research. Such an approach allows ATSDR to protect the confidentiality of Registry enrollees. RESULTS: From 2013 to 2019, a total of 46 institutions around the United States and abroad have leveraged this tool and over 600,000 emails have been sent, resulting in over 2000 patients conservatively recruited for clinical trials and epidemiological studies. Patients between the ages of 60 and 69 had the highest level of participation, whereas those between the ages of 18 and 39 and aged over 80 had the lowest. More males participated (4170/7030, 59.32%) than females (2860/7030, 40.68%). CONCLUSIONS: The National ALS Registry's RNM benefits PALS by connecting them to appropriate ALS research. Simultaneously, the system benefits researchers by expediting recruitment, increasing sample size, and efficiently identifying PALS meeting specific eligibility requirements. As more researchers learn about and use this mechanism, both PALS and researchers can hasten research and expand trial options for PALS.

Reproductive History and Age of Onset for Women Diagnosed with Amyotrophic Lateral Sclerosis: Data from the National ALS Registry: 2010-2018.

BACKGROUND: Amyotrophic lateral sclerosis (ALS) is a neurological disease of largely unknown etiology with no cure. The National ALS Registry is a voluntary online system that collects demographic and reproductive history (females only) data from patients with ALS. We will examine the association between demographic and reproductive history among female patients aged >18 years and various ages of onset for ALS. METHODS: Data from a cross-sectional study were collected and examined for 1,018 female ALS patients. Patient characteristics examined were demographics including race, BMI, and familial history of ALS. Among patients, information on reproductive history, including age at menopause, ever pregnant, and age at first pregnancy was collected. Unadjusted and adjusted logistic regression models were used to estimate OR and 95% CI in this study. RESULTS: Women were more likely to be diagnosed with ALS before age 60 if they were nonwhite (p = 0.015), had attended college (p = 0.0012), had a normal BMI at age 40 (p < 0.0001), completed menopause before age 50 (p < 0.0001), and had never been pregnant (p = 0.046) in the univariate analysis. Women diagnosed with ALS before age 60 were also more likely to have limb site of onset (p < 0.0001). In the multivariate analysis, those who completed menopause before age 50 were more likely to be diagnosed with ALS before age 60 (OR = 1.8, 95% CI: 1.4-2.3) compared with women who completed menopause at or after age 50, after controlling for race, ever pregnant, age at first pregnancy, family history of ALS, education status, smoking history, and BMI at age 40. For women who were diagnosed with ALS before age 50, the odds of them entering menopause before age 50 climb to 48.7 (95% CI: 11.8, 200.9). The mean age of ALS diagnosis for women who completed menopause before age 50 was 58 years and 64 years for women who entered menopause after age 50 (p < 0.0001). CONCLUSION: Women who reported completing menopause before age 50 were significantly more likely to be diagnosed with ALS before age 60 compared with those who reported entering menopause after age 50. More research is needed to determine the relationship between female reproductive history, especially regarding endogenous estrogen exposure and early-onset ALS.

Analysis of Biospecimen Demand and Utilization of Samples from the National Amyotrophic Lateral Sclerosis Biorepository.

Amyotrophic lateral sclerosis (ALS) is a rare neurological condition affecting upper and lower motor neurons. The National ALS Biorepository (referred to as the Biorepository) was initiated in 2015, with biospecimen collection beginning in 2017, as a repository for biospecimens for future ALS research. To help ensure the usefulness of the Biorepository, a biospecimen demand analysis is conducted on an annual basis, as well as an analysis of the utilization of the Biorepository. To determine the types of biospecimens to be collected for the Biorepository, an in-depth initial examination occurred followed by ongoing biospecimen demand and utilization analyses. The initial examination included input from an expert panel, discussions with ALS research experts, review of other ALS biorepositories, assessment of biospecimen demand, and analysis of the biospecimen types historically used in ALS research. Of all biospecimen types reported in the literature, the most frequently used were DNA, postmortem spinal cord, blood, and cerebrospinal fluid; while the frequently reported types of biospecimens used in ALS-related grants were induced pluripotent stem cells, brain, blood, and spinal cord. Continuous analysis of potential sample demand and tissues collected, based on an analysis of the literature and funded grants, and actual sample requests can assist the Biorepository in ensuring that the appropriate samples are available for researchers when they are needed.

Recruitment of population-based controls for ALS cases from the National ALS Registry.

Objective: In 2010, the United States Agency for Toxic Substances and Disease Registry (ATSDR) created the National ALS Registry (Registry) to examine the epidemiology of ALS and potential risk factors. We are currently recruiting population-based controls for an epidemiologic case-control study to examine ALS environmental risk factors using this Registry. To date, we have recruited 181 non-diseased, population-based controls for comparison to Registry cases (n = 280). Here we report our recruitment methods for controls and the associated response rates and costs. Methods: Eligible ALS cases had complete risk factor survey data, DNA analysis, and blood concentrations of persistent organic pollutants (POPs). Age, sex, and county-matched controls were identified from commercial/consumer databases using a targeted landline phone sample. Eligible controls were consented, surveyed, and mailed the POPs' blood analysis consent form. Once consented, phlebotomy was scheduled. Results: We mailed 3760 recruitment letters for 181 potential case-matches across 42 states between 9/2018 and 3/2020. After making phone contact and determining eligibility, 146 controls agreed to participate (response rate = 11.4%, cooperation rate = 22.8%). To date, 127 controls completed the survey and bloodwork. Though controls were matched to cases on age, sex, and county, unmatched characteristics (e.g. smoking) did not differ statistically. Interviewing and incentive costs are estimated at $211.85 per complete participation. Conclusions: Recruiting matched population-based controls for comparison to cases from the Registry for a study involving completion of a detailed survey and blood specimen provision is relatively feasible and cost effective. This recruitment method could be useful for case-control studies of other rare disorders.

The Incidence of Amyotrophic Lateral Sclerosis in Ohio 2016-2018: The Ohio Population-Based ALS Registry.

INTRODUCTION: Amyotrophic lateral sclerosis (ALS) is a fatal, neuromuscular disease with no cure. ALS incidence rates have not been assessed specifically in Ohio, yet the state contains both metropolitan and rural areas with a variety of environmental factors that could contribute to disease etiology. We report the incidence of ALS in Ohio residents diagnosed from October 2016 through September 2018. METHODS: We engaged practitioners from 9 Ohio sites to identify newly diagnosed ALS patients and to complete case report forms with demographic and clinical information. ALS was diagnosed according to the Awaji criteria and classified as either definite, probable, or possible. We developed a method to estimate missing cases using a Poisson regression model to impute cases in counties with evidence of undercounting. RESULTS: We identified 333 newly diagnosed ALS patients residing in Ohio during the 2-year index period and found incidence rates varied in the 88 state counties. After incorporating the estimated 27% of missing cases, the corrected crude annual incidence was 1.96/100,000 person-years, and the age- and gender-standardized incidence was 1.71/100,000 person-years (standardized to the 2010 US census). DISCUSSION/CONCLUSION: The estimated Ohio incidence of ALS is overall similar to that reported in other states in the USA. This study reveals a geospatial variation in incidence within the state, and areas with higher rates warrant future investigation.

Potential for Electric Vehicle Adoption to Mitigate Extreme Air Quality Events in China.

Electric vehicle (EV) adoption promises potential air pollutant and greenhouse gas (GHG) reduction co-benefits. As such, China has aggressively incentivized EV adoption, however much remains unknown with regard to EVs' mitigation potential, including optimal vehicle type prioritization, power generation contingencies, effects of Clean Air regulations, and the ability of EVs to reduce acute impacts of extreme air quality events. Here, we present a suite of scenarios with a chemistry transport model that assess the potential co-benefits of EVs during an extreme winter air quality event. We find that regardless of power generation source, heavy-duty vehicle (HDV) electrification consistently improves air quality in terms of NO2 and fine particulate matter (PM2.5), potentially avoiding 562 deaths due to acute pollutant exposure during the infamous January 2013 pollution episode (~1% of total premature mortality). However, HDV electrification does not reduce GHG emissions without enhanced emission-free electricity generation. In contrast, due to differing emission profiles, light-duty vehicle (LDV) electrification in China consistently reduces GHG emissions (~2 Mt CO2), but results in fewer air quality and human health improvements (145 avoided deaths). The calculated economic impacts for human health endpoints and CO2 reductions for LDV electrification are nearly double those of HDV electrification in present-day (155M vs. 87M US$), but are within ~25% when enhanced emission-free generation is used to power them. Overall, we find only a modest benefit for EVs to ameliorate severe wintertime pollution events, and that continued emission reductions in the power generation sector will have the greatest human health and economic benefits.