ABSTRACT
Many studies have explored the impact of extreme heat on health, but few have investigated localized heat-health outcomes across a wide area. We examined fine-scale variability in vulnerable areas, considering population distribution, local weather, and landscape characteristics. Using 36 different heat event definitions, we identified the most dangerous types of heat events based on minimum, maximum, and diurnal temperatures with varying thresholds and durations. Focusing on California's diverse climate, elevation, and population distribution, we analyzed hospital admissions for various causes of admission (2004-2013). Our matching approach identified vulnerable zip codes, even with small populations, on absolute and relative scales. Bayesian Hierarchical models leveraged spatial correlation. We ranked the 36 heat event types by attributable hospital admissions per zip code and provided code, simulated data, and an interactive web app for reproducibility. Our findings showed high variation in heat-related hospitalizations in coastal cities and substantial heat burdens in the Central Valley. Diurnal heat events had the greatest impact in the Central Valley, while nighttime extreme heat events drove burdens in the southeastern desert. This spatially informed approach guides local policies, prioritizing dangerous heat events to reduce the heat-health burden. The methodology is applicable to other regions, informing early warning systems and characterizing extreme heat impacts.
ABSTRACT
BACKGROUND: Climate change continues to increase the frequency, intensity, and duration of heat events and wildfires, both of which are associated with adverse pregnancy outcomes. Few studies simultaneously evaluated exposures to these increasingly common exposures. OBJECTIVES: We investigated the relationship between exposure to heat and wildfire smoke and preterm birth (PTB). METHODS: In this time-stratified case-crossover study, participants consisted of 85,806 California singleton PTBs (20-36 gestational weeks) from May through October of 2015-2019. Birthing parent ZIP codes were linked to high-resolution daily weather, PM2.5 from wildfire smoke, and ambient air pollution data. Heat day was defined as a day with apparent temperature >98th percentile within each ZIP code and heat wave was defined as ≥2 consecutive heat days. Wildfire-smoke day was defined as a day with any exposure to wildfire-smoke PM2.5. Conditional logistic regression was used to calculate the odds ratio (OR) and 95% confidence intervals (CI) comparing exposures during a hazard period (lags 0-6) compared to control periods. Analyses were adjusted for relative humidity, fine particles, and ozone. RESULTS: Wildfire-smoke days were associated with 3.0% increased odds of PTB (ORlag0: 1.03, CI: 1.00-1.05). Compared with white participants, associations appeared stronger among Black, Hispanic, Asian, and American Indians/Alaskan Native participants. Heatwave days (ORlag2: 1.07, CI: 1.02-1.13) were positively associated with PTB, with stronger associations among those simultaneously exposed to wildfire smoke days (ORlag2: 1.19, CI: 1.11-1.27). Similar findings were observed for heat days and when other temperature metrics (e.g., maximum, minimum) were used. DISCUSSION: Heat and wildfire increased PTB risk with evidence of synergism. As the occurrence and co-occurrence of these events increase, exposure reduction among pregnant people is critical, especially among racial/ethnic minorities.
Subject(s)
Cross-Over Studies , Hot Temperature , Premature Birth , Wildfires , Humans , Female , Adult , Premature Birth/epidemiology , Pregnancy , Hot Temperature/adverse effects , California/epidemiology , Young Adult , Smoke/adverse effects , Air Pollutants/analysis , Particulate Matter/analysisABSTRACT
Extreme heat and ozone are co-occurring exposures that independently and synergistically increase the risk of respiratory disease. To our knowledge, no joint warning systems consider both risks; understanding their interactive effect can warrant use of comprehensive warning systems to reduce their burden. We examined heterogeneity in joint effects (on the additive scale) between heat and ozone at small geographical scales. A within-community matched design with a Bayesian hierarchical model was applied to study this association at the zip code level. Spatially varying relative risks due to interaction (RERI) were quantified to consider joint effects. Determinants of the spatial variability of effects were assessed using a random effects metaregression to consider the role of demographic/neighborhood characteristics that are known effect modifiers. A total of 817,354 unscheduled respiratory hospitalizations occurred in California from 2004 to 2013 in the May to September period. RERIs revealed no additive interaction when considering overall joint effects. However, when considering the zip code level, certain areas observed strong joint effects. A lower median income, higher percentage of unemployed residents, and exposure to other air pollutants within a zip code drove stronger joint effects; a higher percentage of commuters who walk/bicycle, a marker for neighborhood wealth, showed decreased effects. Results indicate the importance of going beyond average measures to consider spatial variation in the health burden of these exposures and predictors of joint effects. This information can be used to inform early warning systems that consider both heat and ozone to protect populations from these deleterious effects in identified areas.
Subject(s)
Air Pollutants/toxicity , Extreme Heat , Hospitalization/statistics & numerical data , Ozone/toxicity , Respiratory System/physiopathology , Air Pollutants/analysis , Bayes Theorem , California , Humans , Ozone/analysis , RiskABSTRACT
Wildfire smoke has been associated with adverse respiratory outcomes, but the impacts of wildfire on other health outcomes and sensitive subpopulations are not fully understood. We examined associations between smoke events and emergency department visits (EDVs) for respiratory, cardiovascular, diabetes, and mental health outcomes in California during the wildfire season June-December 2016-2019. Daily, zip code tabulation area-level wildfire-specific fine particulate matter (PM2.5) concentrations were aggregated to air basins. A "smoke event" was defined as an air basin-day with a wildfire-specific PM2.5 concentration at or above the 98th percentile across all air basin-days (threshold = 13.5 µg/m3). We conducted a two-stage time-series analysis using quasi-Poisson regression considering lag effects and random effects meta-analysis. We also conducted analyses stratified by race/ethnicity, age, and sex to assess potential effect modification. Smoke events were associated with an increased risk of EDVs for all respiratory diseases at lag 1 [14.4%, 95% confidence interval (CI): (6.8, 22.5)], asthma at lag 0 [57.1% (44.5, 70.8)], and chronic lower respiratory disease at lag 0 [12.7% (6.2, 19.6)]. We also found positive associations with EDVs for all cardiovascular diseases at lag 10. Mixed results were observed for mental health outcomes. Stratified results revealed potential disparities by race/ethnicity. Short-term exposure to smoke events was associated with increased respiratory and schizophrenia EDVs. Cardiovascular impacts may be delayed compared to respiratory outcomes.
Subject(s)
Air Pollutants , Wildfires , Air Pollutants/toxicity , Particulate Matter/analysis , California , Emergency Service, Hospital , Environmental Exposure/analysisABSTRACT
Ambient air pollution exposure is associated with exacerbating respiratory illnesses. Race/ethnicity (R/E) have been shown to influence an individual's vulnerability to environmental health risks such as fine particles (PM 2.5). This study aims to assess the R/E disparities in vulnerability to air pollution with regards to respiratory hospital admissions in San Diego County, California where most days fall below National Ambient Air Quality Standards (NAAQS) for daily PM 2.5 concentrations. Daily PM 2.5 levels were estimated at the zip code level using a spatial interpolation using inverse-distance weighting from monitor networks. The association between daily PM 2.5 levels and respiratory hospital admissions in San Diego County over a 15-year period from 1999 to 2013 was assessed with a time-series analysis using a multi-level Poisson regression model. Cochran Q tests were used to assess the effect modification of race/ethnicity on this association. Daily fine particle levels varied greatly from 1 µg/m3 to 75.86 µg/m3 (SD = 6.08 µg/m3) with the majority of days falling below 24-hour NAAQS for PM 2.5 of 35 µg/m3. For every 10 µg/m3 increase in PM 2.5 levels, Black and White individuals had higher rates (8.6% and 6.2%, respectively) of hospitalization for respiratory admissions than observed in the county as a whole (4.1%). Increases in PM 2.5 levels drive an overall increase in respiratory hospital admissions with a disparate burden of health effects by R/E group. These findings suggest an opportunity to design interventions that address the unequal burden of air pollution among vulnerable communities in San Diego County that exist even below NAAQS for daily PM 2.5 concentrations.
Subject(s)
Air Pollutants/adverse effects , Health Status Disparities , Inhalation Exposure/adverse effects , Particulate Matter/adverse effects , Respiratory Tract Diseases/etiology , Air Pollutants/analysis , California/epidemiology , Cost of Illness , Hospitalization/statistics & numerical data , Hospitals , Humans , Inhalation Exposure/analysis , Particulate Matter/analysis , Respiratory Tract Diseases/epidemiology , Respiratory Tract Diseases/ethnologyABSTRACT
BACKGROUND: Associations between ambient air pollution and stillbirth have recently been explored, but most studies have focused on long-term (trimester or gestational averages) rather than short-term (within one week) air pollution exposures. OBJECTIVE: To evaluate whether short-term exposures to criteria air pollutants are associated with increased risk of stillbirth. METHODS: Using air pollution and fetal death certificate data from 1999 to 2009, we assessed associations between acute prenatal air pollution exposure and stillbirth in California. In a time-stratified case-crossover study, we analyzed single day and/or cumulative average days (up to a 6 day lag) of exposure to fine (PM2.5) and coarse particles (PM10-2.5), ozone (O3), nitrogen dioxide (NO2), sulfur dioxide (SO2), and carbon monoxide (CO) for mothers estimated to reside within 10 km of a pollution monitor based on reported zip code. We also examined potential confounding by apparent temperature or co-pollutants, and effect modification by maternal demographic factors, fetal sex, gestational age, and cause of stillbirth. RESULTS: Stillbirth cases in the primary analyses ranged between 1,203 and 13,018, depending on the pollutant. For an IQR increase in SO2 (lag 4), O3 (lag 4), and PM10-2.5 (lag 2), we found a 2.8% (95% confidence interval (CI) 0.2%, 5.5%), 5.8% (95% CI 1.6%, 10.1%), and 6.1% (95% CI 0.1%, 12.4%) increase in the odds of stillbirth, respectively. Additional adjustment by apparent temperature had little effect on the SO2 association but slightly attenuated O3 (adjusted % change: 4.2% (95% CI -0.2%, 8.9%) and PM10-2.5 (5.7% (95% CI -1.1%, 13.0%)) associations, while other co-pollutants had minimal impact. Associations were observed specifically for stillbirths from obstetric complications and in women with higher educational attainment. CONCLUSIONS: This study provides evidence for associations between prenatal short-term air pollution exposure, specifically SO2, O3, and PM10-2.5, and stillbirth in California and warrants replication of findings in other settings.
Subject(s)
Air Pollutants , Air Pollution , Ozone , Air Pollutants/adverse effects , Air Pollutants/analysis , Air Pollution/adverse effects , Air Pollution/analysis , California/epidemiology , Cross-Over Studies , Environmental Exposure/adverse effects , Female , Humans , Nitrogen Dioxide/analysis , Ozone/analysis , Particulate Matter/adverse effects , Particulate Matter/analysis , Pregnancy , Stillbirth/epidemiology , Sulfur Dioxide/analysis , Sulfur Dioxide/toxicityABSTRACT
BACKGROUND: For the past decade, hand, foot and mouth disease (HFMD), caused by entero and coxsackie viruses, has been spreading in Asia, particularly among children, overloading healthcare settings and creating economic hardships for parents. Recent studies have found meteorological factors, such as temperature, are associated with HFMD in Asia. However, few studies have explored the relationship in the United States, although HFMD cases have steadily increased recently. As concerns of climate change grow, we explored the association between temperature and HFMD admissions to the Emergency Department (ED) in California. METHODS: Weekly counts of HFMD for 16 California climate zones were collected from 2005 to 2013. We calculated weekly temperature for each climate zone using an inverse distance-weighting method. For each climate zone stratified by season, we conducted a time-series using Poisson regression models. We adjusted models for weekly averaged relative humidity, average number of HFMD cases in previous weeks and long-term temporal trends. Climate zone estimates were combined to obtain an overall seasonal estimate. We attempted stratified analyses by region, race/ethnicity, and sex to identify sensitive subpopulations. RESULTS: Risk of ED visits for HFMD per 1 °F increase in mean temperature during the same week increased 2.00% (95% confidence intervals 1.15, 2.86%) and 2.35% (1.38, 3.33%) during the warm and cold seasons, respectively. The coastal region showed a higher, though not statistically different, association during the cold season [3.18% (1.99, 4.39)] than the warm season [1.64% (0.47, 2.82)]. CONCLUSIONS: Our findings indicated an association between temperature and ED visits for HFMD, with variation by season and region. Thus, the causative pathogen's ability to persist in the atmosphere may vary by season. Furthermore, the mild and wet winter in the coastal region of California may contribute to different results than studies in Asia. With the onset of climate change, HFMD cases will likely grow in California, warranting further investigation on this relationship, including new populations at-risk.
Subject(s)
Hand, Foot and Mouth Disease , Asia , California/epidemiology , Child , China , Emergency Service, Hospital , Hand, Foot and Mouth Disease/epidemiology , Humans , Incidence , Seasons , TemperatureABSTRACT
BACKGROUND: Exposure to particulate matter air pollution has been associated with cardiovascular disease (CVD) morbidity and mortality; however, most studies have focused on fine particulate matter (PM2.5) exposure and CVD. Coarse particulate matter (PM10-2.5) exposure has not been extensively studied, particularly for long-term exposure, and the biological mechanisms remain uncertain. METHODS: We examined the association between ambient concentrations of PM10-2.5 and inflammatory and hemostatic makers that have been linked to CVD. Annual questionnaire and clinical data were obtained from 1694 women (≥ 55 years old in 1999) enrolled in the longitudinal Study of Women's Health Across the Nation (SWAN) at six study sites from 1999 to 2004. Residential locations and the USEPA air monitoring network measurements were used to assign exposure to one-year PM10-2.5, as well as co-pollutants. Linear mixed-effects regression models were used to describe the association between PM10-2.5 exposure and markers, including demographic, health and other covariates. RESULTS: Each interquartile (4 µg/m3) increase in one-year PM10-2.5 exposure was associated with a 5.5% (95% confidence interval [CI]: 1.8, 9.4%) increase in levels of plasminogen activator inhibitor-1 (PAI-1) and 4.1% (95% CI: - 0.1, 8.6%) increase in high-sensitivity C-creative Protein (hs-CRP). Stratified analyses suggested that the association with PAI-1 was particularly strong in some subgroups, including women who were peri-menopausal, were less educated, had a body mass index lower than 25, and reported low alcohol consumption. The association between PM10-2.5 and PAI-1 remained unchanged with adjustment for PM2.5, ozone, nitrogen dioxide, and carbon monoxide. CONCLUSIONS: Long-term PM10-2.5 exposure may be associated with changes in coagulation independently from PM2.5, and thus, contribute to CVD risk in midlife women.
Subject(s)
Air Pollutants/analysis , Cardiovascular Diseases/epidemiology , Hemostasis , Inflammation/epidemiology , Particulate Matter/analysis , Biomarkers/blood , C-Reactive Protein/analysis , Cardiovascular Diseases/blood , Cohort Studies , Environmental Exposure/analysis , Female , Humans , Inflammation/blood , Menopause/blood , Middle Aged , Particle Size , Plasminogen Activator Inhibitor 1/blood , United States/epidemiologyABSTRACT
Mobile health monitoring via non-invasive wearable sensors is poised to advance telehealth for older adults and other vulnerable populations. Extreme heat and other environmental conditions raise serious health challenges that warrant monitoring of real-time physiological data as people go about their normal activities. Mobile systems could be beneficial for many communities, including elite athletes, military special forces, and at-home geriatric monitoring. While some commercial monitors exist, they are bulky, require reconfiguration, and do not fit seamlessly as a simple wearable device. We designed, prototyped and tested an integrated sensor platform that records heart rate, oxygen saturation, physical activity levels, skin temperature, and galvanic skin response. The device uses a small microcontroller to integrate the measurements and store data directly on the device for up to 48+ h. continuously. The device was compared to clinical standards for calibration and performance benchmarking. We found that our system compared favorably with clinical measures, such as fingertip pulse oximetry and infrared thermometry, with high accuracy and correlation. Our novel platform would facilitate an individualized approach to care, particularly those whose access to healthcare facilities is limited. The platform also can be used as a research tool to study physiological responses to a variety of environmental conditions, such as extreme heat, and can be customized to incorporate new sensors to explore other lines of inquiry.
Subject(s)
Exercise/physiology , Hot Temperature , Monitoring, Physiologic/instrumentation , Wearable Electronic Devices , Accelerometry , Adult , Electric Conductivity , Female , Galvanic Skin Response , Heart Rate , Humans , Linear Models , Male , Middle Aged , Oximetry , Oxygen/blood , Photoplethysmography , Skin Temperature , Spectroscopy, Fourier Transform Infrared , Support Vector Machine , Young AdultABSTRACT
Exposure to ambient fine particulate matter (particulate matter ≤2.5 µm in aerodynamic diameter (PM2.5)) during pregnancy is associated with preterm birth (PTB), a leading cause of infant morbidity and mortality. Results from studies attempting to identify etiologically relevant exposure periods of vulnerability have been inconsistent, possibly because of failure to consider the time-to-event nature of the outcome and lagged exposure effects of PM2.5. In this study, we aimed to identify critical exposure windows for weekly PM2.5 exposure and PTB in California using California birth cohort data from 2005-2010. Associations were assessed using distributed-lag Cox proportional hazards models. We assessed effect-measure modification by race/ethnicity by calculating the weekly relative excess risk due to interaction. For a 10-µg/m3 increase in PM2.5 exposure over the entire period of gestation, PTB risk increased by 11% (hazard ratio = 1.11, 95% confidence interval: 1.09, 1.14). Gestational weeks 17-24 and 36 were associated with increased vulnerability to PM2.5 exposure. We find that non-Hispanic black mothers may be more susceptible to effects of PM2.5 exposure than non-Hispanic white mothers, particularly at the end of pregnancy. These findings extend our knowledge about the existence of specific exposure periods during pregnancy that have the greatest impact on preterm birth.
Subject(s)
Air Pollutants/adverse effects , Maternal Exposure/adverse effects , Particulate Matter/adverse effects , Premature Birth/etiology , Adolescent , Adult , Black or African American , California , Cohort Studies , Female , Humans , Models, Theoretical , Pregnancy , Pregnancy Outcome , Pregnancy Trimesters , Premature Birth/ethnology , Proportional Hazards Models , Young AdultABSTRACT
California has seen a surge in coccidioidomycosis (valley fever), a disease spread by the Coccidioides immitis fungus found in soil throughout the state, particularly in the San Joaquin Valley. We reviewed epidemiologic studies in which outbreak and sporadic cases of coccidioidomycosis were examined, and we considered the possible relationship of these cases to environmental conditions, particularly the state's increasing aridity, drought, and wildfire conditions. Most of the studies we reviewed pertained to cases occupationally acquired in construction, military, archeological, and correctional institutional settings where workers were exposed to dust in C. immitis-endemic areas. A few reviewed outbreaks in the general population related to dust exposure from natural disasters, including an earthquake-associated landslide and a dust storm that carried particles long distances from endemic areas. Although many of California's coccidioidomycosis outbreaks have been occupationally related, changing demographics and new, immunologically naïve populations in dry, endemic areas could expose the general population to C. immitis spores. Given the high rate of infection among workers who, for the most part, are healthy, the general population, including some elderly and immunocompromised individuals, could face additional risk. With climate-related events like drought and wildfires also increasing in endemic areas, research is needed to address the possible associations between these phenomena and coccidioidomycosis outbreaks.
Subject(s)
Coccidioidomycosis/epidemiology , Dust , Environmental Exposure , Adolescent , Adult , Age Factors , Aged , California/epidemiology , Child , Child, Preschool , Climate Change , Coccidioides , Coccidioidomycosis/etiology , Disease Outbreaks , Droughts , Female , Humans , Infant , Male , Middle Aged , Young AdultABSTRACT
BACKGROUND: High ambient temperature has been linked to a number of types of morbidity, such as cardiovascular disease and dehydration. Fewer studies have explored specifically the relationship between ambient temperature and liver, kidney, and urinary system morbidity despite known biological impacts of extreme high temperatures on those systems. OBJECTIVE: We assessed the relationship between temperature and hospitalizations related to selected renal system (urinary stones, urinary tract infections, septicemia, chronic kidney disease, and a composite of selected kidney diseases) and hepatobiliary (biliary tract disease, other liver diseases [e.g. cirrhosis], non-diabetic pancreatic disorders) ailments. METHODS: We compiled data on daily hospitalization counts for hepatobiliary and renal system diseases in California for 1999 through 2009, and matched it with meteorological data. Relationships between temperature and admissions during the warm season (May-October) were assessed at the climate zone-level cumulative over 14 days following exposure using distributed lag non-linear models, with adjustment for time trends and relative humidity, then combined using random-effects meta-regression to create statewide estimates. RESULTS: Higher mean temperatures in the warm season were associated with significant increases in renal admissions for urinary tract infection [% change per 10⯰F: 7.3, 95% CI: 5.6, 9.1], septicemia [% increase: 2.9; 95% CI: 1.5, 4.3], urinary stones [% increase: 15.2; 95% CI: 10.3, 20.4], and composite kidney disease. Additionally, increased temperatures were linked to increased admissions for biliary tract disease, but lower risk of other liver diseases. Some differences in association by race/ethnicity and regional meteorology were observed. CONCLUSIONS: Exposure to higher temperatures was associated with increased risk of multiple renal system hospitalization types, with additional links to specific hepatobiliary morbidities observed.
Subject(s)
Environmental Exposure/statistics & numerical data , Hospitalization/statistics & numerical data , Hot Temperature , Kidney Diseases/epidemiology , Temperature , California/epidemiology , Humans , SeasonsABSTRACT
Few investigations have explored temperature and birth outcomes. In a retrospective cohort study, we examined apparent temperature, a combination of temperature and relative humidity, and term low birth weight (LBW) among 43,629 full-term LBW infants and 2,032,601 normal-weight infants in California (1999-2013). The California Department of Public Health provided birth certificate data, while meteorological data came from the California Irrigation Management Information System, US Environmental Protection Agency, and National Centers for Environmental Information. After considering several temperature metrics, we observed the best model fit for term LBW over the full gestation (per 10-degrees-Fahrenheit (°F) increase in apparent temperature, 13.0% change, 95% confidence interval: 4.1, 22.7) above 55°F, and the greatest association was for third-trimester exposure above 60°F (15.8%, 95% confidence interval: 5.0, 27.6). Apparent temperature during the first month of pregnancy exhibited no significant risk, while the first trimester had a significantly negative association, and second trimester, last month, and last 2 weeks had slightly increased risks. Mothers who were black or older, delivered male infants, or gave birth during the warm season had infants at the highest risks. This study provides further evidence for adverse birth outcomes from heat exposure for vulnerable subgroups of pregnant women.
Subject(s)
Infant, Low Birth Weight , Temperature , Adolescent , Adult , Age Factors , Body Mass Index , California/epidemiology , Female , Humans , Humidity , Infant , Infant, Newborn , Male , Pregnancy , Pregnancy Trimesters/physiology , Racial Groups , Residence Characteristics , Retrospective Studies , Risk Factors , Seasons , Socioeconomic Factors , Young AdultABSTRACT
The association between ambient temperature and morbidity has been explored previously. However, the association between temperature and mental health-related outcomes, including violence and self-harm, remains relatively unexamined. For the period 2005-2013, we obtained daily counts of mental health-related emergency room visits involving injuries with an external cause for 16 California climate zones from the California Office of Statewide Health Planning and Development and combined them with data on mean apparent temperature, a combination of temperature and humidity. Using Poisson regression models, we estimated climate zone-level associations and then used random-effects meta-analyses to produce overall estimates. Analyses were stratified by season (warm: May-October; cold: November-April), race/ethnicity, and age. During the warm season, a 10°F (5.6°C) increase in same-day mean apparent temperature was associated with 4.8% (95% confidence interval (CI): 3.6, 6.0), 5.8% (95% CI: 4.5, 7.1), and 7.9% (95% CI: 7.3, 8.4) increases in the risk of emergency room visits for mental health disorders, self-injury/suicide, and intentional injury/homicide, respectively. High temperatures during the cold season were also positively associated with these outcomes. Variations were observed by race/ethnicity, age group, and sex, with Hispanics, whites, persons aged 6-18 years, and females being at greatest risk for most outcomes. Increasing mean apparent temperature was found to have acute associations with mental health outcomes and intentional injuries, and these findings warrant further study in other locations.
Subject(s)
Emergency Service, Hospital/statistics & numerical data , Mental Health/statistics & numerical data , Temperature , Adolescent , Adult , Age Factors , Aged , California/epidemiology , Child , Child, Preschool , Ethnicity/statistics & numerical data , Female , Humans , Male , Middle Aged , Racial Groups/statistics & numerical data , Seasons , Self-Injurious Behavior/epidemiology , Sex Factors , Suicide/statistics & numerical data , Violence/statistics & numerical data , Young AdultABSTRACT
BACKGROUND: Exposure to ambient fine particulate matter (PM2.5) has been linked with premature mortality, but sources of PM2.5 have been less studied. METHODS: We evaluated associations between source-specific PM2.5 exposures and cause-specific short-term mortality in eight California locations from 2002 to 2011. Speciated PM2.5 measurements were source-apportioned using Positive Matrix Factorization into eight sources and combined with death certificate data. We used time-stratified case-crossover analysis with conditional logistic regression by location and meta-analysis to calculate pooled estimates. RESULTS: Biomass burning was associated with all-cause mortality lagged 2 days after exposure (lag2) (% changelag2 in odds per interquartile range width increase in biomass burning PM2.5 = 0.8, 95% confidence interval [CI] = 0.2, 1.4), cardiovascular (% changelag2 = 1.3, 95% CI = 0.3, 2.4), and ischemic heart disease (% changelag2 = 2.0, 95% CI = 0.6, 3.5). Vehicular emissions were associated with increases in cardiovascular mortality (% changelag0 = 1.4, 95% CI = 0.0, 2.9). Several other sources exhibited positive associations as well. Many findings persisted during the cool season. Warm season biomass burning was associated with respiratory/thoracic cancer mortality (% changelag1 = 5.9, 95% CI = 0.7, 11.3), and warm season traffic was associated with all-cause (% changelag0 = 1.9, 95% CI = 0.1, 3.6) and cardiovascular (% changelag0 = 2.9, 95% CI = 0.1, 5.7) mortality. CONCLUSIONS: Our results suggest that acute exposures to biomass burning and vehicular emissions are linked with cardiovascular mortality, with additional sources (i.e., soil, secondary nitrate, secondary sulfate, aged sea salt, and chlorine sources) showing associations with other specific mortality types.
Subject(s)
Mortality , Particulate Matter/adverse effects , Adolescent , Adult , Aged , California/epidemiology , Child , Child, Preschool , Educational Status , Female , Humans , Infant , Infant, Newborn , Logistic Models , Male , Middle Aged , Particulate Matter/analysis , Racial Groups/statistics & numerical data , Vehicle Emissions/toxicity , Weather , Young AdultABSTRACT
The stillbirth rate in the United States is relatively high, but limited evidence is available linking stillbirth with fine particulate matter (PM2.5), its chemical constituents and sources. In this study, we explored associations between cause-specific stillbirth and prenatal exposures to those pollutants with using live birth and stillbirth records from eight California locations during 2002-2009. ICD-10 codes were used to identify cause of stillbirth from stillbirth records. PM2.5 total mass and chemical constituents were collected from ambient monitors and PM2.5 sources were quantified using Positive Matrix Factorization. Conditional logistic regression was applied using a nested case-control study design (N = 32,262). We found that different causes of stillbirth were associated with different PM2.5 sources and/or chemical constituents. For stillbirths due to fetal growth, the odds ratio (OR) per interquartile range increase in gestational age-adjusted exposure to PM2.5 total mass was 1.23 (95% confidence interval (CI): 1.06, 1.44). Similar associations were found with resuspended soil (OR=1.25, 95% CI: 1.10, 1.42), and secondary ammonium sulfate (OR=1.45, 95% CI: 1.18, 1.78). No associations were found between any pollutants and stillbirths caused by maternal complications. This study highlighted the importance of investigating cause-specific stillbirth and the differential toxicity levels of specific PM2.5 sources and chemical constituents.
Subject(s)
Maternal Exposure/adverse effects , Particulate Matter/toxicity , Stillbirth/epidemiology , Adult , California/epidemiology , Cause of Death , Female , Humans , Infant, Newborn , Male , Particulate Matter/chemistry , Pregnancy , Young AdultABSTRACT
Investigators have examined how heat waves or incremental changes in temperature affect health outcomes, but few have examined both simultaneously. We utilized distributed lag nonlinear models (DLNM) to explore temperature associations and evaluate possible added heat wave effects on hospitalizations in 16 climate zones throughout California from May through October 1999-2009. We define heat waves as a period when daily mean temperatures were above the zone- and month-specific 95th percentile for at least two consecutive days. DLNMs were used to estimate climate zone-specific non-linear temperature and heat wave effects, which were then combined using random effects meta-analysis to produce an overall estimate for each. With higher temperatures, admissions for acute renal failure, appendicitis, dehydration, ischemic stroke, mental health, non-infectious enteritis, and primary diabetes were significantly increased, with added effects from heat waves observed for acute renal failure and dehydration. Higher temperatures also predicted statistically significant decreases in hypertension admissions, respiratory admissions, and respiratory diseases with secondary diagnoses of diabetes, though heat waves independently predicted an added increase in risk for both respiratory types. Our findings provide evidence that both heat wave and temperature exposures can exert effects independently.
Subject(s)
Hospitalization/statistics & numerical data , Hot Temperature/adverse effects , Infrared Rays/adverse effects , Adult , California , Child, Preschool , Humans , Infant , Middle Aged , Young AdultSubject(s)
Air Pollution , Particulate Matter , Air Pollution/analysis , Humans , Outcome Assessment, Health CareABSTRACT
BACKGROUND: Particulate matter (PM) has been documented to contribute to preterm delivery. However, few studies have investigated the relationships between individual constituents of fine PM (PM2.5 ) and preterm delivery, and factors that may modify their associations. METHODS: In this study, we examined the associations between several prenatal exposure metrics to PM2.5 and 23 constituents of PM2.5 and preterm delivery in California from 2000 to 2006. In a retrospective cohort study including 231 637 births, we conducted logistic regression analyses adjusting for maternal, infant, temporal, geographic, and neighbourhood characteristics. RESULTS: We observed increased risk for preterm delivery with full-gestational exposure for several PM2.5 constituents. Per interquartile range increase, ammonium (21.2%, 95% confidence interval (CI) 17.1, 25.4), nitrate (18.1%, 95% CI 14.9, 21.4) and bromine (16.7%, 95% CI 13.2, 20.3) had some of the largest increased risks. Alternatively, some PM2.5 constituents were inversely associated with preterm delivery, including chlorine (-8.2%, 95% CI -10.3, -6.0), sodium (-13.2%, 95% CI -15.2, -11.3), sodium ion (-11.9%, 95% CI -14.1, -9.6) and vanadium (-19.2%, 95% CI -25.3, -12.6). Greater associations between PM2.5 constituents and preterm delivery were observed for Blacks and Asians, older mothers, and those with some college education compared to their reference groups, as well as for births with gestational ages from 32 to 34 weeks. CONCLUSIONS: PM2.5 constituents ammonium, nitrate and bromine, often linked to traffic and biomass combustion, were most associated with increased risk of preterm delivery in California. Certain demographic subgroups may be particularly impacted.