IMPORTANCE Evidence of whether severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes coronavirus disease 2019 , can be transmitted as an aerosol (ie, airborne) has substantial public health implications.OBJECTIVE To investigate potential transmission routes of SARS-CoV-2 infection with epidemiologic evidence from a COVID-19 outbreak. DESIGN, SETTING, AND PARTICIPANTSThis cohort study examined a community COVID-19 outbreak in Zhejiang province. On January 19, 2020, 128 individuals took 2 buses (60 [46.9%] from bus 1 and 68 [53.1%] from bus 2) on a 100-minute round trip to attend a 150-minute worship event. The source patient was a passenger on bus 2. We compared risks of SARS-CoV-2 infection among at-risk individuals taking bus 1 (n = 60) and bus 2 (n = 67 [source patient excluded]) and among all other individuals (n = 172) attending the worship event. We also divided seats on the exposed bus into high-risk and low-risk zones according to the distance from the source patient and compared COVID-19 risks in each zone. In both buses, central air conditioners were in indoor recirculation mode.MAIN OUTCOMES AND MEASURES SARS-CoV-2 infection was confirmed by reverse transcription polymerase chain reaction or by viral genome sequencing results. Attack rates for SARS-CoV-2 infection were calculated for different groups, and the spatial distribution of individuals who developed infection on bus 2 was obtained. RESULTSOf the 128 participants, 15 (11.7%) were men, 113 (88.3%) were women, and the mean age was 58.6 years. On bus 2, 24 of the 68 individuals (35.3% [including the index patient]) received a diagnosis of COVID-19 after the event. Meanwhile, none of the 60 individuals in bus 1 were infected. Among the other 172 individuals at the worship event, 7 (4.1%) subsequently received a COVID-19 diagnosis. Individuals in bus 2 had a 34.3% (95% CI, 24.1%-46.3%) higher risk of getting COVID-19 compared with those in bus 1 and were 11.4 (95% CI, 5.1-25.4) times more likely to have COVID-19 compared with all other individuals attending the worship event. Within bus 2, individuals in high-risk zones had moderately, but nonsignificantly, higher risk for COVID-19 compared with those in the low-risk zones. The absence of a significantly increased risk in the part of the bus closer to the index case suggested that airborne spread of the virus may at least partially explain the markedly high attack rate observed. CONCLUSIONS AND RELEVANCEIn this cohort study and case investigation of a community outbreak of COVID-19 in Zhejiang province, individuals who rode a bus to a worship event with a patient with COVID-19 had a higher risk of SARS-CoV-2 infection than individuals who rode another bus to the same event. Airborne spread of SARS-CoV-2 seems likely to have contributed to the high attack rate in the exposed bus. Future efforts at prevention and control must consider the potential for airborne spread of the virus.

comments. The views expressed herein are those of the authors and do not necessarily reflect the views of the National Bureau of Economic Research. NBER working papers are circulated for discussion and comment purposes. They have not been peerreviewed or been subject to the review by the NBER Board of Directors that accompanies official NBER publications.

IMPORTANCE Studies examining the association of low to moderate drinking with various cognitive functions have yielded mixed findings. OBJECTIVE To investigate whether associations exist between low to moderate alcohol drinking and cognitive function trajectories or rates of change in cognitive function from middle age to older age among US adults. DESIGN, SETTING, AND PARTICIPANTS A prospective cohort study of participants drawn from the Health and Retirement Study (HRS), a nationally representative sample of US adults, with mean (SD) follow-up of 9.1 (3.1) years. In total, 19 887 participants who had their cognitive functions measured in the HRS starting in 1996 through 2008 and who had participated in at least 3 biennial surveys were included. The data analysis was conducted from June to November 2019. EXPOSURES Alcohol consumption and aging. MAIN OUTCOMES AND MEASURES Trajectories and annual rates of change for the cognitive domains of mental status, word recall, and vocabulary and for the total cognitive score, which was the sum of the mental status and word recall scores. Participants were clustered into 2 cognitive function trajectories for each cognition measure assessed based on their scores at baseline and through at least 3 biennial surveys: a consistently low trajectory (representing low cognitive scores throughout the study period) and a consistently high trajectory (representing high cognitive scores throughout the study period). RESULTS The mean (SD) age of 19 887 participants was 61.8 (10.2) years, and the majority of the HRS participants were women (11 943 [60.1%]) and of white race/ethnicity (16 950 [85.2%]). Low to moderate drinking (<8 drinks per week for women and <15 drinks per week for men) was significantly associated with a consistently high cognitive function trajectory and a lower rate of cognitive decline.

The first major insurance expansion of the Affordable Care Act - a provision requiring insurers to allow dependents to remain on parents' health insurance until turning 26 - took effect in September 2010. We estimate this mandate's impacts on numerous outcomes related to health care access, preventive care utilization, risky behaviors, and self-assessed health. We estimate difference-in-differences models with 23-25 year olds as the treatment group and 27-29 year olds as the control group. For the full sample, the dependent coverage provision increased the probabilities of having health insurance, a primary care doctor, and excellent self-assessed health, while reducing body mass index. However, the mandate also increased risky drinking and did not lead to any significant increases in preventive care utilization. Subsample analyses reveal particularly large gains for men and college graduates.

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