Costs of Air Pollution in California's San Joaquin Valley: A Societal Perspective of the Burden of Asthma on Emergency Departments and Inpatient Care.

Introduction: The San Joaquin Valley (SJV) is often recognized as one of the most polluted regions in the US. Periods of pollution exposure are associated with increased health burden related to respiratory inflammation and undermined lung function, which aggravates respiratory diseases such as asthma and leads to symptoms such as coughing, wheezing, or difficulty breathing. Asthma costs US$ 82 billion annually in healthcare costs, missed work and school in the US. Methods: Employing a societal perspective, a cost of illness design was combined with environmental epidemiological methods to analyze the economic impact of O3, NO2, and PM2.5-related adverse respiratory health outcomes amongst SJV residents who attended the emergency department (ED) or were hospitalized in 2016. Results: Asthma exacerbations monetized value ranged from US$ 3353 to US$ 5003 per ED visit and for hospital admissions US$ 2584 per inpatient day for adults 65 years and older to US$ 3023 per child. The estimated value to society in healthcare costs, productivity losses, school absences, and opportunity costs from air pollution adverse health outcomes totaled US$ 498,014,124 in ED visits and US$ 223,552,720 in hospital admissions for the SJV population in 2016. The marginal reduction in the background concentrations of pollutants would avert 21,786 ED adverse events and 19,328 hospitalizations from the health burden on the SJV population or US$ 8,024,505 cost savings due to O3, US$ 82,482,683 from NO2 reductions, and US$ 46,214,702 from decreased concentration of PM2.5. Conclusion: This study provides evidence that air pollution is a negative externality that imposes substantial social, environmental, and healthcare costs on the SJV. Furthermore, the region would avert significant adverse health outcomes realizing economic savings by reducing air pollution and exposures.

The moderating role of housing quality on concentrated poverty and asthma-related emergency department visits among Hispanics/Latinos.

BACKGROUND: Rates of asthma-related emergency department visits have been shown to vary significantly by place (i.e. neighborhood) and race/ethnicity. The moderating factors of asthmatic events among Hispanic/Latino-specific populations are known to a much lesser degree. OBJECTIVE: To assess the extent to which housing moderates the effect of poverty on Hispanic/Latino-specific asthma-related emergency department (ED) visits at an ecological level. METHODS: Using data from the Office of Statewide Health Planning and Development (OSHPD) and the 2016-2017 U.S. Census, a cross-sectional ecological analysis at the census tract-level was conducted. Crosswalk files from the U.S. Department of Housing and Urban Development were used to associate zip codes to census tracts. Negative binomial regression was used to estimate rate ratios. RESULTS: The effect of poverty on asthma-related ED visits was significantly moderated by the median year of housing structures built. The effect of mid-level poverty (RR = 1.57, 95% CI 1.27, 1.95) and high-level poverty (RR = 1.47, 95% CI 1.22, 1.78) in comparison to low-level poverty, was significantly greater among census tracts with housing built prior to 1965 in comparison to census tract with housing built between 1965 and 2020. CONCLUSION: Communities with older housing structures tend to be associated with increased Hispanic/Latino ED visits apart from affluent communities.

Dietary patterns related to total mortality and cancer mortality in the United States.

PURPOSE: This study investigated the association between dietary patterns, total mortality, and cancer mortality in the United States. METHODS: We identified the four major dietary patterns at baseline from 13,466 participants of the NHANES III cohort using principal component analysis (PCA). Dietary patterns were categorized into 'prudent' (fruits and vegetables), 'western' (red meat, sweets, pastries, oils), 'traditional' (red meat, legumes, potatoes, bread), and 'fish and alcohol'. We estimated hazard ratios for total mortality, and cancer mortality using Cox regression models. RESULTS: A total of 4,963 deaths were documented after a mean follow-up of 19.59 years. Higher adherence to the 'prudent' pattern was associated with the lowest risk of total mortality (5th vs. 1st quintile HR 0.90, 95% CI 0.82-0.98), with evidence that all-cause mortality decreased as consumption of the pattern increased. No evidence was found that the 'prudent' pattern reduced cancer mortality. The 'western' and the 'traditional' patterns were associated with up to 22% and 16% increased risk for total mortality (5th vs. 1st quintile HR 1.22, 95% CI 1.11-1.34; and 5th vs. 1st quintile HR 1.16, 95% CI 1.06-1.27, respectively), and up to 33% and 15% increased risk for cancer mortality (5th vs. 1st quintile HR 1.33, 95% CI 1.10-1.62; and 5th vs. 1st quintile HR 1.15, 95% CI 1.06-1.24, respectively). The associations between adherence to the 'fish and alcohol' pattern and total mortality, and cancer mortality were not statistically significant. CONCLUSION: Higher adherence to the 'prudent' diet decreased the risk of all-cause mortality but did not affect cancer mortality. Greater adherence to the 'western' and 'traditional' diet increased the risk of total mortality and mortality due to cancer.

Nitrogen dioxide and asthma emergency department visits in California, USA during cold season (November to February) of 2005 to 2015: A time-stratified case-crossover analysis.

Nitrogen dioxide (NO2) is responsible for aggravating respiratory diseases, particularly asthma. The aim of this study is to investigate the association between NO2 exposure and asthma emergency department (ED) visits during the cold season (November-February) in five populated locations (Sacramento, San Francisco, Fresno, Los Angeles, and San Diego) of California from 2005 to 2015 (1320 Days). Conditional logistic regression models were used to obtain the odds ratio (OR) and 95% confidence interval (CI) associated with a 5 ppb increase in NO2 concentration for the 19,735 ED visits identified. An increase in NO2 exposure increased the odds of having asthma ED visits for the studied population. The potential effect modification by sex (female and male), race (White, Black, Hispanic, and Asian), and age (2-5, 6-18, 19-40, 41-64, and ≥65) was explored. A 5 ppb increase in the concentration of NO2 during lag 0-30 was associated with a 56% increase in the odds of having an asthma ED visit (OR = 1.560, CI: 1.428-1.703). Sex was not found to be a modifier. Asthma ED visits among all the races/ethnicities (except Asians) were associated with NO2 exposure. Whites had the highest OR 75% (OR = 1.750, CI: 1.417-2.160) at lag 0-30 in response to NO2 exposure. The association between NO2 exposure and asthma ED visits was positive among all age groups except for 19 to 40 years old; the OR was higher among 2 to 18 year old (at lag 0-30: age group 2-5 (OR = 1.699, CI: 1.399-2.062), and age group 6-18 (OR = 1.568, CI 1.348-1.825)). For stratification by location, San Diego and Fresno were found to have the highest OR, compared to the other studied locations.

Electronic cigarette (e-cigarette) use and frequency of asthma symptoms in adult asthmatics in California.

INTRODUCTION: Electronic cigarettes use is increasing in the United States. One motive for e-cigarette's popularity is that they wean from combustible cigarettes. Smokers perceive electronic cigarette products as healthier than cigarette smoking and as a useful tool for smoking cessation. However, research has indicated the use of electronic cigarettes may have harmful effects on respiratory function even with short-term use. Respiratory effects of e-cigarette use among asthmatics are little understood. OBJECTIVE: The aim of this study was to determine the association between e-cigarette use and frequency of asthma symptoms among adult asthmatics in California from 2015-2016. METHODS: This cross-sectional study included a total of 1277 adult asthmatics. The presence of asthma was based on an adult's self-reported doctor diagnosis. The analysis was controlled for age, education, sex, race, body mass index, and smoking status. RESULTS: E-cigarette use was associated with increased odds of having more frequent asthma symptoms (OR = 1.69, CI: 1.20-2.39, p = 0.002; ORadj = 1.65, CI: 1.09-2.49, p = 0.016). Male e-cigarette users were more likely to have more frequent asthma symptoms compared to male nonusers (OR = 1.90, CI: 1.13-3.19, p = 0.015; ORadj = 2.42, CI: 1.28-4.55, p = 0.006). No differences were found between female e-cigarette users and nonusers (OR = 1.43, CI: 0.86-2.37, p = 0.162; ORadj = 1.26, CI: 0.72-2.18, p = 0.162). CONCLUSION: Our findings suggest that e-cigarette use is associated with more frequent asthma symptoms and disproportionally affects male asthmatics.

Methyl-bromide and asthma emergency department visits in California, USA from 2005 to 2011.

Objective: Urban monitors of Methyl bromide (MBr), not typically near application sites, are used to investigate the impact of ambient concentrations on asthma Emergency Department (ED) visits.Methods: 4262 ED visits from August to February of 2005 to 2011 in Central and Southern California were selected from California's Office of Statewide Health Planning and Development (OSHPD). A bidirectional-symmetric case-crossover study design using conditional logistic regression model was used to obtain the odds ratio (OR) and 95% confidence interval associated with a 0.01 ppb (interquartile range) increase in MBr.Results: The population sample was comprised of 46.0% male and 53.9% females. Ethnic groups included 32.0% Non-Hispanic White, 23.5% Non-Hispanic Black, and 44.4% Hispanic. Age distribution was between 2 and 5 years old (11.6%), 6 and 18 years old (23.5%), 19 and 40 years old (29.3%), 41 and 64 years old (24.1%), and 65 or older (6.9%). There was a positive association between MBr and asthma ED visits among Non-Hispanic Blacks [OR: 1.065 (95% confidence intervals: 1.019, 1.108)] and Hispanics [OR: 1.107 (95% confidence intervals: 1.043, 1.173)], while Non-Hispanic Whites did not have an association with asthma ED visits. Positive association between MBr and asthma ED visits was found only among 6 to 18 [OR: 1.071 (95% confidence intervals: 1.016, 1.125)] years old.Conclusion: An increase in MBr concentration was found to be associated with an increase of the odds of having asthma ED visits in California among 6 to 18 years old and disproportionately affects Non-Hispanic Blacks and Hispanics over Non-Hispanic Whites.

The association between 1,3-dichloropropene and asthma emergency department visits in California, USA from 2005 to 2011: a bidirectional-symmetric case crossover study.

Objective: The ever-increasing rate of pesticide use in California farmlands is of great concern due to its potential toxicity on human health. In this study, the association between short term exposure to 1,3-dichloropropene (1,3-D) and asthma emergency department (ED) visits in central and southern California from 2005 to 2011 is investigated.Methods: 3878 ED visits were identified from 2005 to 2011 (1064 days). Conditional logistic regression models were used to obtain the odds ratio (OR) associated with 0.01 ppb increase in 1,3-D. Potential effect modification by sex, race/ethnicity (Non-Hispanic White, Non-Hispanic Black, or Hispanic), and age (2-5, 6-18, 19-40, 41-64 or ≥ 65) are investigated.Results: It was found that a 0.01 ppb increase in 1,3-D at the event day is associated with 13.5% [OR = 1.135, 95% CI: 1.123, 1.149] increase in the odds of having asthma ED visits in central and southern California during October to February of 2005 to 2011. Race had a positive association between 1,3-D and asthma ED visits among Non-Hispanic Black [OR= 1.095 95% CI: 1.035, 1.155] and Hispanic [OR= 1.121 95% CI: 1.064, 1.179]; while Non-Hispanic Whites had no association. Positive association for age was found between 1,3-D and asthma ED visits among patients 2 to 5 [OR= 1.065 95% CI: 1.020, 1.133], 6 to 18 [OR= 1.142 95% CI: 1.086, 1.196], and 19 to 40 [OR= 1.023 95% CI: 1.015, 1.073] years old.Conclusion: These findings suggest a 0.01 ppb increase in 1,3-D concentration increases the odds of having asthma ED visits.

Incident command post exposure to polycyclic aromatic hydrocarbons and particulate matter during a wildfire.

Wildland firefighters engaged in fire suppression activities are often exposed to hazardous air pollutants such as polycyclic aromatic hydrocarbons (PAHs) and particulate matter (PM2.5) during wildfires with no respiratory protection. Although the most significant exposures to smoke likely occur on the fireline, wildland firefighters may also be exposed at the incident command post (ICP), an area designated for wildfire suppression support operations. Our objective was to characterize exposures of PAHs and PM2.5 near an ICP during a wildfire event in California. We collected area air samples for PAHs and PM2.5, during the first 12 days of a wildfire event. PAH area air samples were actively collected in 12-hr shifts (day and night) using XAD4-coated quartz fiber filters and XAD2 sorbent tubes and analyzed for 17 individual PAHs. Hourly area PM2.5 concentrations were measured with an Environmental Beta Attenuation Monitor. Most PAH concentrations generally had similar concentrations during the day and night. PM2.5 concentrations were higher during the day, due to increased fire activity, than at night. The highest concentrations of the 17 PAHs measured were for naphthalene, phenanthrene, and retene. The location of an ICP may be a critical factor in reducing these potential exposures to firefighters during wildfire events. Additionally, exposures could be reduced by utilizing clean air tents or sleeping trailers with HEPA filtration or setting up smaller camps in less smokey areas closer to the fireline for firefighters. Although measured exposures to PAHs for firefighters from smoke are lower at an ICP, these exposures still contribute to the overall cumulative work exposures.

Cumulative Impact of Environmental Pollution and Population Vulnerability on Pediatric Asthma Hospitalizations: A Multilevel Analysis of CalEnviroScreen.

The CalEnviroScreen created by the Office of Environmental Health Hazard Assessment, Sacramento, USA, is a place-based dataset developed to measure environmental and social indicators that are theorized to have cumulative health impacts on populations. The objective of this study was to examine the extent to which the composite scores of the CalEnviroScreen tool are associated with pediatric asthma hospitalization. This was a retrospective analysis of California hospital discharge data from 2010 to 2012. Children who were hospitalized for asthma-related conditions, were aged 0-14 years, and resided in California were included in analysis. Rates of hospitalization for asthma-related conditions among children residing in California were calculated. Poisson multilevel modeling was used to account for individual- and neighborhood-level risk factors. Every unit increase in the CalEnviroScreen Score was associated with an increase of 1.6% above the mean rate of pediatric asthma hospitalizations (rate ratio (RR) = 1.016, 95% confidence interval (CI) = 1.014-1.018). Every unit increase in racial/ethnic segregation and diesel particulate matter was associated with an increase of 1.1% and 0.2% above the mean rate of pediatric asthma, respectively (RR = 1.011, 95% CI = 1.010-1.013; RR = 1.002, 95% CI = 1.001-1.004). The CalEnviroScreen is a unique tool that combines socioecological factors and environmental indicators to identify vulnerable communities with major health disparities, including pediatric asthma hospital use. Future research should identify mediating factors that contribute to community-level health disparities.

Ozone pollution and asthma emergency department visits in the Central Valley, California, USA, during June to September of 2015: a time-stratified case-crossover analysis.

Objective: The San Joaquin Valley (SJV) exceeds the state and national standards for ozone (O3). This study investigates whether short-term exposure to O3 is associated with asthma emergency department (ED) visits. Methods: We identified 1,101 ED visits in June-September of 2015 in SJV, California, who lived within 15 km of active air monitors. Conditional logistic regression models were used to obtain the odds ratio (OR) and 95% confidence interval (CI) associated with an interquartile (IQR) increase in ozone. We explored the potential effect modification by sex (female and male), race (White, Black and Hispanic), age (2-5, 6-18, 19-40, 41-64 and > = 65) and county (Merced, Madera, Kings, Fresno and Kern). Results: An IQR range (18.1 ppb) increase in O3 exposure three days before an asthma attack (lag 3) was associated with a 6.6% [OR: 1.066 (95% CI: 1.032, 1.082)] increase in the odds of having an asthma ED visit. The overall ORs differed across age groups and races/ethnicities, with strongest for children aged 6-18 years [OR: 1.219 (95% CI: 1.159, 1.280)], adults 19-40 years [OR: 1.102 (95% CI: 1.053, 1.154)] and Blacks [OR: 1.159 (95% CI: 1.088, 1.236)], respectively. O3 exposure was not positively associated with asthma ED visits for Whites, while it was for other underrepresented groups. Fresno had the highest number of asthma ED visits and positive association among all five counties. Conclusion: We found that O3 exposure is associated with asthma ED visits in the SJV.

Nitrogenous air pollutants and ozone exposure in the central Sierra Nevada and White Mountains of California - Distribution and evaluation of ecological risks.

Ammonia (NH3), nitric oxide (NO), nitrogen dioxide (NO2), nitric acid (HNO3), and ozone (O3) were measured in summers of 2012 and 2013 with passive samplers. Nine monitoring sites were on W-E transect (511 to 3490 m) across central Sierra Nevada Mountains (SNM), and five sites on elevational gradient (1237 to 4346 m) in White Mountains (WM) of California. Levels of pollutants were similar in 2012 and 2013 in all sites. NH3, NO2, and HNO3 were highest near highly polluted Central Valley of California (CVC): maximum summer season means 7.8 µg m-3, 3.0 ppb, and 3.0 µg m-3, respectively. Regional background for NH3, NO2, and HNO3 in SNM occurred >20 km from CVC and >1500 m with seasonal averages: 2.1-4.8 µg m-3; 0.8-1.7 ppb; 1.0-1.8 µg m-3, respectively, during two seasons. Levels of NH3, NO2, and HNO3 in WM remote locations were similar: 1.2-3.3 µg m-3, 0.6-1.1 ppb, and 1.0-1.3 µg m-3, respectively. Seasonal mean O3 (38-60 ppb) in SNM did not change with distance from CVC nor elevation. In WM, O3 and NO mixing ratios were 41-61 ppb and 2.3-4.1 ppb, respectively, increasing with elevation. Even the lowest NH3 concentrations determined in this study were higher than NH3 continental background. This fact, as well as high values of Nreduced/Noxidized near CVC of 1.9 in 2012 and 2.0 in 2013, decreasing with distance to 0.7 in 2012 and 0.8 in 2013, show importance of NH3 emissions from CVC as a contributor to N deposition and ecological impacts in SNM. The phytotoxic O3 indices, AOT40 and W126, for selected sites on SNM and WM transects, showed high potential for negative O3 impacts on vegetation, including forest trees. CAPSULE: Elevated NH3, NO2, and HNO3 on the western slopes of the Sierra Nevada Mountains (SNM) near the Central Valley of California (CVC) decreased with distance from CVC and elevation to regional background levels also recorded at high elevation sites of the White Mountains (WM).

Health care access, concentrated poverty, and pediatric asthma hospital care use in California's San Joaquin Valley: A multilevel approach.

BACKGROUND: California's San Joaquin Valley is a region with a history of poverty, low health care access, and high rates of pediatric asthma. It is important to understand the potential barriers to care that challenge vulnerable populations. OBJECTIVE: The objective was to describe pediatric asthma-related utilization patterns in the emergency department (ED) and hospital by insurance coverage as well as to identify contributing individual-level indicators (age, sex, race/ethnicity, and insurance coverage) and neighborhood-level indicators of health care access. METHODS: This was a retrospective study based on secondary data from California hospital and ED records 2007-2012. Children who used services for asthma-related conditions, were aged 0-14 years, Hispanic or non-Hispanic white, and resided in the San Joaquin Valley were included in the analysis. Poisson multilevel modeling was used to control for individual- and neighborhood-level factors. RESULTS: The effect of insurance coverage on asthma ED visits and hospitalizations was modified by the neighborhood-level percentage of concentrated poverty (RR = 1.01, 95% CI = 1.01-1.02; RR = 1.03, 95% CI = 1.02-1.04, respectively). The effect of insurance coverage on asthma hospitalizations was completely explained by the neighborhood-level percentage of concentrated poverty. CONCLUSIONS: Observed effects of insurance coverage on hospital care use were significantly modified by neighborhood-level measures of health care access and concentrated poverty. This suggests not only an overall greater risk for poor children on Medi-Cal, but also a greater vulnerability or response to neighborhood social factors such as socioeconomic status, community cohesiveness, crime, and racial/ethnic segregation.

Using National Ambient Air Quality Standards for fine particulate matter to assess regional wildland fire smoke and air quality management.

Wildland fire is an important ecological process in the California Sierra Nevada. Personal accounts from pre-20th century describe a much smokier environment than present day. The policy of suppression beginning in the early 20th century and climate change are contributing to increased megafires. We use a single particulate monitoring site at the wildland urban interface to explore impacts from prescribed, managed, and full suppression wildland fires from 2006 to 2015 producing a contextual assessment of smoke impacts over time at the landscape level. Prescribed fire had little effect on local fine particulate matter (PM2.5) air quality with readings typical of similar non-fire times; hourly and daily good to moderate Air Quality Index (AQI) for PM2.5, maximum hourly concentrations 21-103 µg m-3, and mean concentrations between 7.7 and 13.2 µg m-3. Hourly and daily AQI was typically good or moderate during managed fires with 3 h and one day reaching unhealthy while the site remained below National Ambient Air Quality Standards (NAAQS), with maximum hourly concentrations 27-244 µg m-3, and mean concentrations 6.7-11.7 µg m-3. The large high intensity fire in this area created the highest short term impacts (AQI unhealthy for 4 h and very unhealthy for 1 h), 11 unhealthy for sensitive days, and produced the only annual value (43.9 µg m-3) over the NAAQS 98th percentile for PM2.5 (35 µg m-3). Pinehurst remained below the federal standards for PM2.5 when wildland fire in the local area was managed to 7800 ha (8-22% of the historic burn area). Considering air quality impacts from smoke using the NAAQS at a landscape level over time can give land and air managers a metric for broader evaluation of smoke impacts particularly when assessing ecologically beneficial fire. Allowing managers to control the amount and timing of individual wildland fire emissions can help lessen large smoke impacts to public health from a megafire.

Understanding Public Views about Air Quality and Air Pollution Sources in the San Joaquin Valley, California.

The San Joaquin Valley of California has poor air quality and high rates of asthma. Surveys were collected from 744 residents of the San Joaquin Valley from November 2014 to January 2015 to examine the public's views about air quality. The results of this study suggest that participants exposed to high PM2.5 (particulate matter less than 2.5 microns in size) concentrations perceived air pollution to be of the worst quality. Air quality in the San Joaquin Valley was primarily perceived as either moderate or unhealthy for sensitive groups. Females perceived air pollution to be of worse quality compared to males. Participants perceived unemployment, crime, and obesity to be the top three most serious community problems in the San Joaquin Valley. Participants viewed cars and trucks, windblown dust, and factories as the principle contributors to air pollution in the area. There is a need to continue studying public perceptions of air quality in the San Joaquin Valley with a more robust survey with more participants over several years and seasons.

Occupational Exposure to Polycyclic Aromatic Hydrocarbon of Wildland Firefighters at Prescribed and Wildland Fires.

Wildland firefighters suppressing wildland fires or conducting prescribed fires work long shifts during which they are exposed to high levels of wood smoke with no respiratory protection. Polycyclic aromatic hydrocarbons (PAHs) are hazardous air pollutants formed during incomplete combustion. Exposure to PAHs was measured for 21 wildland firefighters suppressing two wildland fires and 4 wildland firefighters conducting prescribed burns in California. Personal air samples were actively collected using XAD4-coated quartz fiber filters and XAD2 sorbent tubes. Samples were analyzed for 17 individual PAHs through extraction with dichloromethane and gas chromatograph-mass spectrometer analysis. Naphthalene, retene, and phenanthrene were consistently the highest measured PAHs. PAH concentrations were higher at wildland fires compared to prescribed fires and were highest for firefighters during job tasks that involve the most direct contact with smoke near an actively burning wildland fire. Although concentrations did not exceed current occupational exposure limits, wildland firefighters are exposed to PAHs not only on the fire line at wildland fires, but also while working prescribed burns and while off-duty. Characterization of occupational exposures from wildland firefighting is important to understand better any potential long-term health effects.

Soda consumption and hospital admissions among Californian adults with asthma.

INTRODUCTION: Asthma prevalence has been increasing consistently since 1995 in California. Recent studies have found that consuming soda and sugar-containing drinks may pose a risk for asthma. Research that examines the relationship between soda intake and asthma among adult asthmatics is limited. OBJECTIVE: This study investigated the relationship between sugar-sweetened soda consumption and asthma hospitalization among adult asthmatics in California. METHODS: This cross-sectional study was based on the 2011-2012 California Health Interview Survey (CHIS) data and included 3,784 adults who were diagnosed with asthma by a doctor and who currently reported either that they still had asthma, or that they had suffered from an asthma attack in the last 12 months. The analysis was survey weighted. The exposure variable was soda intake measured as the number of times soda was consumed in the last week. The health outcome measure was overnight hospital admission due to asthma. Logistic regression was used to examine the association between soda consumption and overnight hospital admission after adjusting for age, education, sex, race/ethnicity, weight status, smoking status, and self-rated health. RESULTS: Adults with asthma who drank soda three or more times per week reported higher odds of overnight hospitalization (adjusted odds ratio = 2.77, 95% CI: 1.51-5.10, p = 0.001). CONCLUSIONS: Our findings suggest that efforts designed to limit soda consumption would benefit asthma suffers by reducing hospital admissions. This, however, needs further research to confirm a direct causal association.

Latino and Non-Latino Perceptions of the Air Quality in California's San Joaquin Valley.

The San Joaquin Valley (SJV) of California has poor air quality, high rates of asthma, and high rates of obesity. Informational campaigns aimed at increasing awareness of the health impacts of poor air quality and promoting behavior change need to be tailored to the specific target audiences. The study examined perceptions of air quality, perceived health impacts, and methods of accessing information about air quality between Latinos and other groups in the SJV. Residents of the SJV (n = 744) where surveyed via one of three methods: community organizations (256), public locations (251), and an internet panel (237). The results suggest that people perceive the air quality in their region to be generally unhealthy, particularly for sensitive groups. The air quality is more likely to be reported as being unhealthy by people with health problems and less unhealthy by Latinos and people who report regularly exercising. Latinos are more likely to report working outdoors regularly, but also more likely to report being able to reduce their exposure if the air quality is unhealthy. The results report differences in informational sources about air quality, suggesting that informational campaigns should target high risk groups using a variety of media.

Air-Quality Impacts and Intake Fraction of PM2.5 during the 2013 Rim Megafire.

The 2013 Rim Fire was the third largest wildfire in California history and burned 257 314 acres in the Sierra Nevada Mountains. We evaluated air-quality impacts of PM2.5 from smoke from the Rim Fire on receptor areas in California and Nevada. We employed two approaches to examine the air-quality impacts: (1) an evaluation of PM2.5 concentration data collected by temporary and permanent air-monitoring sites and (2) an estimation of intake fraction (iF) of PM2.5 from smoke. The Rim Fire impacted locations in the central Sierra nearest to the fire and extended to the northern Sierra Nevada Mountains of California and Nevada monitoring sites. Daily 24-h average PM2.5 concentrations measured at 22 air monitors had an average concentration of 20 µg/m3 and ranged from 0 to 450 µg/m3. The iF for PM2.5 from smoke during the active fire period was 7.4 per million, which is slightly higher than representative iF values for PM2.5 in rural areas and much lower than for urban areas. This study is a unique application of intake fraction to examine emissions-to-exposure for wildfires and emphasizes that air-quality impacts are not only localized to communities near large fires but can extend long distances and affect larger urban areas.

A statistical model for determining impact of wildland fires on Particulate Matter (PM2.5) in Central California aided by satellite imagery of smoke.

As the climate in California warms and wildfires become larger and more severe, satellite-based observational tools are frequently used for studying impact of those fires on air quality. However little objective work has been done to quantify the skill these satellite observations of smoke plumes have in predicting impacts to PM2.5 concentrations at ground level monitors, especially those monitors used to determine attainment values for air quality under the Clean Air Act. Using PM2.5 monitoring data from a suite of monitors throughout the Central California area, we found a significant, but weak relationship between satellite-observed smoke plumes and PM2.5 concentrations measured at the surface. However, when combined with an autoregressive statistical model that uses weather and seasonal factors to identify thresholds for flagging unusual events at these sites, we found that the presence of smoke plumes could reliably identify periods of wildfire influence with 95% accuracy.

Wildland fire management and air quality in the southern Sierra Nevada: using the Lion Fire as a case study with a multi-year perspective on PM(2.5) impacts and fire policy.

Management of fire is an important and controversial policy issue. Active fire suppression has led to a backlog of fuels, limited the ecological benefits of fire, and reduced short-term smoke impacts likely delaying these emissions to future generations over a larger spatial extent. Smoke impacts can be expected to increase as fire size and intensity increase and the fuel backlog is consumed; whether through reintroduction of fire under desirable conditions or through stand replacing fire. Land Management Agencies would like to increase the use of naturally ignited fires to burn during favorable conditions as a way to reduce catastrophic fires. This study provides information about the levels of air quality impacts expected from these types of fires and discusses some of the policy controversies of managed fire that propagate inconsistencies between agencies and enter the public discourse. The Lion Fire, a primarily low intensity 8,370 ha fire that was extensively monitored for Particulate Matter less than 2.5 microns (PM2.5), is used to quantify impacts to air quality. PM2.5 monitoring sites are used to assess exposure, public health impacts, and subsequently quantify annual air quality during a year with a fire that is within the historic normal fire size and intensity for this area. Ground level PM2.5 impacts were found to be localized with 99% of the hourly Air Quality Index readings in the moderate or good category for the sites impacted by the fire. PM2.5 concentrations at sites nearest the fire were below annual federal air quality standards for PM2.5 with annual 98th percentile at the most impacted sites (Johnsondale, Kernville, and Camp Nelson) of 35.0, 34.0, and 28.0 µg m(-3) respectively. Smoke impacts to PM2.5 concentrations were not found to reach the populated Central Valley. The findings suggest that this type of fire can be implemented with minimal public health impacts thus allowing an opportunity for air and fire managers to alter policy to allow additional burning in an area with severe anthropogenic air pollution and where frequent widespread fire is both beneficial and inevitable. The more extensive air quality impacts documented with large high intensity fire may be averted by embracing the use of fire to prevent unwanted high intensity burns. A widespread increase in the use of fire for ecological benefit may provide the resiliency needed in Sierra Nevada forests as well as be the most beneficial to public health through the reduction of single dose exposure to smoke and limiting impacts spatially.