Dataset Information

Estimate of OH trends over one decade in North American cities.

ABSTRACT: The hydroxyl radical (OH) is the most important oxidant on global and local scales in the troposphere. Urban OH controls the removal rate of primary pollutants and triggers the production of ozone. Interannual trends of OH in urban areas are not well documented or understood due to the short lifetime and high spatial heterogeneity of OH. We utilize machine learning with observational inputs emphasizing satellite remote sensing observations to predict surface OH in 49 North American cities from 2005 to 2014. We observe changes in the summertime OH over one decade, with wide variation among different cities. In 2014, compared to the summertime OH in 2005, 3 cities show a significant increase of OH, whereas, in 27 cities, OH decreases in 2014. The year-to-year variation of OH is mapped to the decline of the NO2 column. We conclude that these cities in this analysis are either in the NOx-limited regime or at the transition from a NOx suppressed regime to a NOx-limited regime. The result emphasizes that, in the future, controlling NOx emissions will be most effective in regulating the ozone pollution in these cities.

SUBMITTER: Zhu Q

PROVIDER: S-EPMC9169711 | biostudies-literature | 2022 Apr

REPOSITORIES: biostudies-literature

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Estimate of OH trends over one decade in North American cities.

Zhu Qindan Q Laughner Joshua L JL Cohen Ronald C RC

Proceedings of the National Academy of Sciences of the United States of America 20220411 16

The hydroxyl radical (OH) is the most important oxidant on global and local scales in the troposphere. Urban OH controls the removal rate of primary pollutants and triggers the production of ozone. Interannual trends of OH in urban areas are not well documented or understood due to the short lifetime and high spatial heterogeneity of OH. We utilize machine learning with observational inputs emphasizing satellite remote sensing observations to predict surface OH in 49 North American cities from 2 ...[more]

PMID: 35412909

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Project description:ObjectivesThere is a growing body of evidence that in the absence of Chlamydia trachomatis and/or Neisseria gonorrhoeae, Mycoplasma genitalium and bacterial vaginosis (BV) are associated with cervicitis. We aimed to describe infections detected among cervicitis cases over a decade and establish how commonly M. genitalium and BV were detected among non-chlamydial/non-gonococcal cases to inform testing and treatment practices.MethodsWe conducted a retrospective case-series to determine the number of cervicitis cases diagnosed with genital infections (C. trachomatis, N. gonorrhoeae, M. genitalium and BV) among women attending the largest public sexual health service in Australia from 2011 to 2021. We determined the proportion of cervicitis cases with one or more genital infections detected, and trends in testing and detection of each infection over time.ResultsOver a decade 813 cervicitis cases were diagnosed; 421 (52%, 95%CI: 48%-55%) had no infection detected; 226/729 (31%, 95%CI: 28%-35%) had BV, 163/809 (20%, 95%CI: 17%-23%) C. trachomatis, 48/747 (6%, 95%CI: 5%-8%) M. genitalium, and 13/793 (2%, 95%CI: 1%-3%) N. gonorrhoeae. Of the 665 (82%) cases tested for all four infections, 268 (40%) had one infection and 73 (11%) had >1 infection detected. Of the 517/665 (78%) non-chlamydial/non-gonococcal cases, 164 (32%) had BV and 16 (3%) had M. genitalium as the sole infections detected; a further 13 cases (3%) were co-infected with BV and M. genitalium. The proportion of cases tested for BV (90%) did not change overtime, but detection increased from 32% to 45% (Ptrend < 0.001). The proportion of cases tested for M. genitalium increased from 84% in 2011 to 96% in 2019 (Ptrend = 0.006), with M. genitalium-detection in cervicitis increasing from 3% to 7% (Ptrend = 0.046).ConclusionsIn our study population, chlamydia or gonorrhoea were not detected in ∼75% of cervicitis cases; 1 in 3 of these cases had BV and/or M. genitalium, and both increased in prevalence over time. These data highlight the need for clinicians to consider BV and M. genitalium when assessing and managing cervicitis.

Dataset Information

Estimate of OH trends over one decade in North American cities.

Publications

Estimate of OH trends over one decade in North American cities.

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