A Risk and Decision Analysis Framework to Evaluate Future PM2.5 Risk: A Case Study in Los Angeles-Long Beach Metro Area.
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SUBMITTER: He B
PROVIDER: S-EPMC8124696 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:The speciation, oxidation states, and relative abundance of iron (Fe) phases in PM2.5 samples from two locations in urban Los Angeles were investigated using a combination of bulk and spatially resolved, element-specific spectroscopy and microscopy methods. Synchrotron X-ray absorption spectroscopy (XAS) of bulk samples in situ (i.e., without extraction or digestion) was used to quantify the relative fractions of major Fe phases, which were corroborated by spatially resolved spectro-microscopy measurements. Ferrihydrite (amorphous Fe(III)-hydroxide) comprised the largest Fe fraction (34-52%), with hematite (α-Fe2O3; 13-23%) and magnetite (Fe3O4; 10-24%) identified as major crystalline oxide components. An Fe-bearing phyllosilicate fraction (16-23%) was fit best with a reference spectrum of a natural illite/smectite mineral, and metallic Fe(0) was a relatively small (2-6%) but easily identified component. Sizes, morphologies, oxidation state, and trace element compositions of Fe-bearing PM from electron microscopy, electron energy loss spectroscopy (EELS), and scanning transmission X-ray microscopy (STXM) revealed variable and heterogeneous mixtures of Fe species and phases, often associated with carbonaceous material with evidence of surface oxidation. Ferrihydrite (or related Fe(III) hydroxide phases) was ubiquitous in PM samples. It forms as an oxidation or surface alteration product of crystalline Fe phases, and also occurs as coatings or nanoparticles dispersed with other phases as a result of environmental dissolution and re-precipitation reactions. The prevalence of ferrihydrite (and adsorbed Fe(III) has likely been underestimated in studies of ambient PM because it is non-crystalline, non-magnetic, more soluble than crystalline phases, and found in complex mixtures. Review of potential sources of different particle types suggests that the majority of Fe-bearing PM from these urban sites originates from anthropogenic activities, primarily abrasion products from vehicle braking systems and engine emissions from combustion and/or wear. These variable mixtures have a high probability for electron transfer reactions between Fe, redox-active metals such as copper, and reactive carbon species such as quinones. Our findings suggest the need to assess biological responses of specific Fe-bearing phases both individually and in combination to unravel mechanisms of adverse health effects of particulate Fe.
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Project description:The role of medication use in multiple myeloma (MM) risk remains unclear.The Los Angeles County Multiple Myeloma Case-Control Study, comprising 278 MM cases and individually matched neighborhood controls, provided data to assess associations between medication use and MM risk. Odds ratios (OR) and 95 % confidence intervals (CI) were estimated using conditional logistic regression.Erythromycin (ever) use was associated with increased MM risk (OR 1.85, 95 % CI 1.13-3.03). This association was restricted to men (OR 3.77, 95 % CI 1.72-8.29) and was especially apparent among men who took two or more courses of erythromycin (OR 4.68, 95 % CI 1.70-12.87).Compared to females, males have lower levels of cytochrome P450 3A4 (CYP3A4), for which erythromycin is both a substrate and inhibitor. Use of CYP3A4-inhibiting drugs such as erythromycin in men may thus result in even lower levels of CYP3A4 and, consequently, higher levels of CYP3A4-metabolized substances. These results could potentially provide clues to explain discrepancies in MM incidence by sex. Consortial efforts to confirm these associations are warranted.
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Project description:Background. The National Council on Aging's Aging Mastery Program (AMP) aims to help older adults implement health behavior and lifestyle changes to promote healthy aging and social engagement. The purpose of the present community-partnered evaluation was to test the effectiveness of AMP implementation in Los Angeles County to improve participants' quality of life, global physical and mental health, and patient activation. Method. A modified randomized wait-list controlled trial design was used to examine experimental, quasi-experimental, and dose-response evidence in five senior centers. Participants completed questionnaires at baseline and after the 10-week intervention, self-reporting their overall quality of life, physical health, mental health, and patient activation. Results. Experimental, intention-to-treat analyses found AMP assignment did not affect any measured outcomes (n = 71). Quasi-experimental, "as treated" analyses (n = 106) controlling for study site and sociodemographic characteristics indicated that participants who attended AMP reported more positive changes in global mental health than the control group. Attending AMP was not associated with changes in quality of life, physical health, or patient activation. Dose-response analyses among AMP participants who attended at least one class (n = 75) found that attending more classes was not significantly associated with greater improvements in mental health. Conclusions. Experimental, intention-to-treat analyses did not support effectiveness of AMP on quality of life, physical or mental health, or patient activation; quasi-experimental analyses found attending AMP was associated with improvements in mental health. Recruitment challenges and participants' nonadherence with condition assignment decreased our ability to detect effects. https://clinicaltrials.gov/ct2/show/NCT03342729?term=Aging+Mastery+Program&rank=1 .
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Project description:Los Angeles County has among the lowest smoking rates of large urban counties in the USA. Nevertheless, concerning disparities persist as high smoking prevalence is found among certain subgroups. We calculated adult smoking prevalence in the incorporated cities of Los Angeles County in order to identify cities with high smoking prevalence. The prevalence was estimated by a model-based small area estimation method with utilization of three data sources, including the 2007 Los Angeles County Health Survey, the 2000 Census, and the 2007 Los Angeles County Population Estimates and Projection System. Smoking prevalence varied considerably across cities, with a more than fourfold difference between the lowest (5.3%) and the highest prevalence (21.7%). Higher smoking prevalence was generally found in socioeconomically disadvantaged cities. The disparities identified here add another layer of data to our knowledge of the health inequities experienced by low-income urban communities and provide much sought data for local tobacco control. Our study also demonstrates the feasibility of providing credible local estimates of smoking prevalence using the model-based small area estimation method.
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Project description:Oxidative potential (OP) has been proposed as a possible integrated metric for particles smaller than 2.5 μm in diameter (PM2.5) to evaluate adverse health outcomes associated with particulate air pollution exposure. Here, we investigate how OP depends on sources and chemical composition and how OP varies by land use type and neighborhood socioeconomic position in the Los Angeles area. We measured OH formation (OPOH), dithiothreitol loss (OPDTT), black carbon, and 52 metals and elements for 54 total PM2.5 samples collected in September 2019 and February 2020. The Positive Matrix Factorization source apportionment model identified four sources contributing to volume-normalized OPOH: vehicular exhaust, brake and tire wear, soil and road dust, and mixed secondary and marine. Exhaust emissions contributed 42% of OPOH, followed by 21% from brake and tire wear. Similar results were observed for the OPDTT source apportionment. Furthermore, by linking measured PM2.5 and OP with census tract level socioeconomic and health outcome data provided by CalEnviroScreen, we found that the most disadvantaged neighborhoods were exposed to both the most toxic particles and the highest particle concentrations. OPOH exhibited the largest inverse social gradients, followed by OPDTT and PM2.5 mass. Finally, OPOH was the metric most strongly correlated with adverse health outcome indicators.
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Project description:ImportanceThe COVID-19 pandemic has had disproportionate effects on racial and ethnic minority communities, where preexisting clinical and social conditions amplify health and social disparities. Many of these communities report lower vaccine confidence and lower receipt of the COVID-19 vaccine. Understanding factors that influence the multifaceted decision-making process for vaccine uptake is critical for narrowing COVID-19-related disparities.ObjectiveTo examine factors that members of multiethnic communities at high risk for COVID-19 infection and morbidity report as contributing to vaccine decision-making.Design, setting, and participantsThis qualitative study used community-engaged methods to conduct virtual focus groups from November 16, 2020, to January 28, 2021, with Los Angeles County residents. Potential participants were recruited through email, video, and telephone outreach to community partner networks. Focus groups were stratified by self-identified race and ethnicity as well as age. Transcripts were analyzed using reflexive thematic analysis.Main outcomes and measuresThemes were categorized by contextual, individual, and vaccine-specific influences using the World Health Organization's Vaccine Hesitancy Matrix categories.ResultsA total of 13 focus groups were conducted with 70 participants (50 [71.4%] female) who self-identified as American Indian (n = 17 [24.3%]), Black/African American (n = 17 [24.3%]), Filipino/Filipina (n = 11 [15.7%]), Latino/Latina (n = 15 [21.4%]), or Pacific Islander (n = 10 [14.3%]). A total of 39 participants (55.7%) were residents from high-poverty zip codes, and 34 (48.6%) were essential workers. The resulting themes included policy implications for equitable vaccine distribution: contextual influences (unclear and unreliable information, concern for inequitable access or differential treatment, references to mistrust from unethical research studies, accessibility and accommodation barriers, eligibility uncertainty, and fears of politicization or pharmaceutical industry influence); social and group influences (inadequate exposure to trusted messengers or information, altruistic motivations, medical mistrust, and desire for autonomy); and vaccination-specific influences (need for vaccine evidence by subpopulation, misconceptions on vaccine development, allocation ambiguity, vaccination safety preferences, the importance of perceiving vaccine equity, burden of vaccine scheduling, cost uncertainty, and desire for practitioner recommendation).Conclusions and relevanceIn this qualitative study, participants reported a number of factors that affected their vaccine decision-making, including concern for inequitable vaccine access. Participants endorsed policy recommendations and strategies to promote vaccine confidence. These results suggest that support of informed deliberation and attainment of vaccine equity will require multifaceted, multilevel policy approaches that improve COVID-19 vaccine knowledge, enhance trust, and address the complex interplay of sociocultural and structural barriers to vaccination.
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Project description:Fine resolution spatial variability in pneumonia hospitalization may identify correlates with socioeconomic, demographic and environmental factors. We performed a retrospective study within the Fairview Health System network of Minnesota. Patients 2 months of age and older hospitalized with pneumonia between 2011 and 2015 were geocoded to their census block group, and pneumonia hospitalization risk was analyzed in relation to socioeconomic, demographic and environmental factors. Spatial analyses were performed using Esri's ArcGIS software, and multivariate Poisson regression was used. Hospital encounters of 17 840 patients were included in the analysis. Multivariate Poisson regression identified several significant associations, including a 40% increased risk of pneumonia hospitalization among census block groups with large, compared with small, populations of ⩾65 years, a 56% increased risk among census block groups in the bottom (first) quartile of median household income compared to the top (fourth) quartile, a 44% higher risk in the fourth quartile of average nitrogen dioxide emissions compared with the first quartile, and a 47% higher risk in the fourth quartile of average annual solar insolation compared to the first quartile. After adjusting for income, moving from the first to the second quartile of the race/ethnic diversity index resulted in a 21% significantly increased risk of pneumonia hospitalization. In conclusion, the risk of pneumonia hospitalization at the census-block level is associated with age, income, race/ethnic diversity index, air quality, and solar insolation, and varies by region-specific factors. Identifying correlates using fine spatial analysis provides opportunities for targeted prevention and control.
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