Exposure to bioaerosol allergens such as pollen can cause exacerbations of allergenic airway disease (AAD) in sensitive populations, and thus cause serious public health problems. Assessing these health impacts by linking the airborne pollen levels, concentrations of respirable allergenic material, and human allergenic response under current and future climate conditions is a key step toward developing preventive and adaptive actions. To that end, a regional-scale pollen emission and transport modeling framework was developed that treats allergenic pollens as non-reactive tracers within the WRF/CMAQ air-quality modeling system. The Simulator of the Timing and Magnitude of Pollen Season (STaMPS) model was used to generate a daily pollen pool that can then be emitted into the atmosphere by wind. The STaMPS is driven by species-specific meteorological (temperature and/or precipitation) threshold conditions and is designed to be flexible with respect to its representation of vegetation species and plant functional types (PFTs). The hourly pollen emission flux was parameterized by considering the pollen pool, friction velocity, and wind threshold values. The dry deposition velocity of each species of pollen was estimated based on pollen grain size and density. An evaluation of the pollen modeling framework was conducted for southern California for the period from March to June 2010. This period coincided with observations by the University of Southern California's Children's Health Study (CHS), which included O3, PM2.5, and pollen count, as well as measurements of exhaled nitric oxide in study participants. Two nesting domains with horizontal resolutions of 12 km and 4 km were constructed, and six representative allergenic pollen genera were included: birch tree, walnut tree, mulberry tree, olive tree, oak tree, and brome grasses. Under the current parameterization scheme, the modeling framework tends to underestimate walnut and peak oak pollen concentrations, and tends to overestimate grass pollen concentrations. The model shows reasonable agreement with observed birch, olive, and mulberry tree pollen concentrations. Sensitivity studies suggest that the estimation of the pollen pool is a major source of uncertainty for simulated pollen concentrations. Achieving agreement between emission modeling and observed pattern of pollen releases is the key for successful pollen concentration simulations.
Existing research has found a positive association between cognitive function and residence in a socioeconomically advantaged neighborhood. Yet, the mechanisms underlying this relationship have not been empirically investigated. This study tests the hypothesis that neighborhood socioeconomic structure is related to cognitive function partly through the availability of neighborhood physical and social resources (e.g. recreational facilities, community centers and libraries), which promote cognitively beneficial activities such as exercise and social integration.
Using data from a representative survey of community-dwelling adults in the City of Chicago (N = 949 adults age 50 and over) we assessed cognitive function with a modified version of the Telephone Interview for Cognitive Status (TICS) instrument. Neighborhood socioeconomic structure was derived from US Census indicators. Systematic Social Observation was used to directly document the presence of neighborhood resources on the blocks surrounding each respondent’s residence.
Using multilevel linear regression, residence in an affluent neighborhood had a net positive effect on cognitive function after adjusting for individual risk factors. For white respondents, the effects of neighborhood affluence operated in part through a greater density of institutional resources (e.g. community centers) that promote cognitively beneficial activities such as physical activity. Stable residence in an elderly neighborhood was associated with higher cognitive function (potentially due to greater opportunities for social interaction with peers), but long term exposure to such neighborhoods was negatively related to cognition.
Neighborhood resources have the potential to promote “cognitive reserve” for adults who are aging in place in an urban setting.
cognitive function; neighborhood; urban health; elderly
Social network analysis has become central to understanding the spread of infectious diseases and behavioral risks for chronic disease. Networks are typically seen as conduits for spread of disease or risk factors thereof. However, social relationships also reduce incidence of chronic disease, and potentially infectious diseases as well. Seldom are these opposing effects considered simultaneously. We show how and why diarrheal disease spreads more slowly to and within rural Ecuadorian villages that are more remote from the area’s population center. Reduced contact with outside individuals partially accounts for remote villages’ relatively lower prevalence of diarrheal disease. But equally or more important is greater density of social ties between individuals in remote communities, which facilitates spread of individual and collective practices that reduce transmission of diarrheal disease.
Diarrheal disease; social networks; infectious diseases; social epidemiology; development and health
The fatty acid composition of eggs is highly reflective of the diet of the laying hen; therefore, nutritionally important fatty acids can be increased in eggs in order to benefit human health. To explore the factors affecting the hen's metabolism and deposition of fatty acids of interest, the current research was divided into two studies. In Study 1, the fatty acid profile of eggs from Bovan White hens fed either 8%, 14%, 20%, or 28% of the omega-6 fatty acid, linoleic acid (LA) (expressed as a percentage of total fatty acids), and an additional treatment of 14% LA containing double the amount of saturated fat (SFA) was determined. Omega-6 fatty acids and docosapentaenoic acid (DPA) in the yolk were significantly (P < 0.05) increased, and oleic acid (OA) and eicosapentaenoic acid (EPA) were significantly decreased with an increasing dietary LA content. In Study 2, the fatty acid and sensory profiles were determined in eggs from Shaver White hens fed either (1) 15% or 30% of the omega-3 fatty acid, alpha-linolenic acid (ALA) (of total fatty acids), and (2) low (0.5), medium (1), or high (2) ratios of SFA: LA+OA. Increasing this ratio resulted in marked increases in lauric acid, ALA, EPA, DPA, and docosahexaenoic acid (DHA), with decreases in LA and arachidonic acid. Increasing the dietary ALA content from 15% to 30% (of total fatty acids) did not overcome the DHA plateau observed in the yolk. No significant differences (P ≥ 0.05) in aroma or flavor between cooked eggs from the different dietary treatments were observed among trained panelists (n = 8). The results showed that increasing the ratio of SFA: LA+OA in layer diets has a more favorable effect on the yolk fatty acid profile compared to altering the LA content at the expense of OA, all while maintaining sensory quality.
Descriptive analysis; docosahexaenoic acid; eggs; laying hens; omega-3; saturated fat; sensory
This study compared the hypertension prevalence, awareness, treatment and control in Chicago, Illinois and Detroit, Michigan to that of the general United States population (aged ≥ 25 years) for the period 2001–2003. We examined whether and how much 1) urban populations have less favorable hypertension-related outcomes and 2) the rates of racial/ethnic minorities lag behind those of Whites in order to determine if the national data understate the magnitude of hypertension-related outcomes and racial/ethnic disparities in two large cities in the Midwestern region of the United States and perhaps others.
Unstandardized and standardized hypertension-related outcome rates were estimated.
The hypertension-related outcomes among Chicago and Detroit residents lag behind the United States by 8%–14% and 10%–18% points, respectively. Additionally, this study highlights the complexity of the racial/ethnic differences in hypertension-related outcomes, where within each population, Blacks were more likely to have hypertension and to be aware of their hypertension status than Whites, and no less likely to be treated. Conversely, Hispanics were less likely to have hypertension and also less likely to be aware of their status when they do have hypertension when compared to Whites.
At a time when efficacious treatment for hypertension has been available for more than 50 years, continued racial/ethnic differences in the prevalence, awareness, treatment and control of hypertension is among public health’s greatest challenges. To achieve the proposed national hypertension-related goals, future policies must consider the social context of hypertension within central cities of urban areas. (Ethn Dis. 2012;22:391–397)
Hypertension; Minority Health; Population; Urban Health
The implications of recent weight gain trends for widening social disparities in body weight in the United States are unclear. Using an intersectional approach to studying inequality, and the longitudinal and nationally representative American’s Changing Lives study (19862001/2002), we examine social disparities in body mass index trajectories during a time of rapid weight gain in the United States. Results reveal complex interactive effects of gender, race, socioeconomic position and age, and provide evidence for increasing social disparities, particularly among younger adults. Most notably, among individuals who aged from 25–39 to 45–54 during the study interval, low-educated and low-income black women experienced the greatest increase in BMI, while high-educated and high-income white men experienced the least BMI growth. These new findings highlight the importance of investigating changing disparities in weight intersectionally, using multiple dimensions of inequality as well as age, and also presage increasing BMI disparities in the U.S. adult population.
Despite lower rates of mortality and some forms of morbidity, Latinos report worse self-rated health (SRH) than Whites. These inconsistencies have raised questions about the validity of SRH for cross-ethnic comparisons and its use as a measure of health disparities. We examine whether the translation of this measure into Spanish helps explain these patterns.
We analyzed levels of SRH under different language conditions using cross-sectional data from the 2002 Chicago Community Adult Health Study and the 2003 Behavioral Risk Factor Surveillance System.
Being interviewed in Spanish was associated with significantly higher odds of rating one’s health as fair/poor in both data sets, and adjusting for language of interview substantially reduced the SRH gap between whites and Latinos. Spanish-language interviewees were also more likely to rate their health as “fair” (“regular” in Spanish) than any other response category, after adjusting for age, sex, socioeconomic position, health conditions, and other factors. The association between being interviewed in Spanish and reporting “fair”/“regular” health was strongest when contrasted against response categories representing better health (good, very good, and excellent).
The findings support the hypothesis that the translation of the English word “fair” to “regular” induces Spanish-speaking respondents to report worse levels of health than they otherwise would in English. We recommend caution in interpreting this widely used instrument—especially when making racial/ethnic comparisons—and propose experimental research using different translations of this measure to arrive at one that better equates its meaning in Spanish and English.
Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis is hypothesized to be an important pathway linking socioeconomic position and chronic disease.
This paper tests the association between education and the diurnal rhythm of salivary cortisol.
Up to 8 measures of cortisol (mean of 5.38 per respondent) over two days were obtained from 311 respondents, aged 18–70, drawn from the 2001–2002 Chicago Community Adult Health Study. Multi-level models with linear splines were used to estimate waking level, rates of cortisol decline, and area-under-the-curve over the day, by categories of education.
Lower education (0–11 years) was associated with lower waking levels of cortisol, but not the rate of decline of cortisol, resulting in a higher area-under-the-curve for more educated respondents throughout the day.
This study found evidence of lower cortisol exposure among individuals with less education and thus does not support the hypothesis that less education is associated with chronic over-exposure to cortisol.
This study examines the role of neighborhood context in the accumulation of biological risk factors and racial/ethnic and socioeconomic disparities.
Data come from face-to-face interviews and blood collection on a probability sample of adults (n=549) in the 2002 Chicago Community Adult Health Study. Following the approach of prior studies, we constructed an index of cumulative biological risk (CBR) by counting how many of eight biomarkers exceeded clinically defined criteria for “high risk”: systolic and diastolic blood pressure, resting heart rate, hemoglobin A1c, C-reactive protein, waist size, and total and HDL cholesterol. Data are presented as incidence rate ratios (IRR) based on generalized linear models with a Poisson link function and population-average estimates with robust standard errors.
Non-Hispanic blacks (n=200), Hispanics (n=149), and people with low (n=134) and moderate (n=275) education had significantly higher numbers of biological risks than their respective reference groups (IRR=1.48, 1.59, 1.62, and 1.48, respectively, with p-values <0.01). Black-white (p<0.001) and Hispanic-white (p<0.003) disparities in CBR remained significant after adjusting for individual-level socioeconomic position and behavioral factors, while individual-level controls substantially diminished the low/high (p<0.069) and moderate/high (p<0.042) educational differences. Estimating “within-neighborhood” disparities to adjust for neighborhood context fully explained the black-white gap in CBR (p<0.542) and reduced the Hispanic-white gap to borderline significance (p<0.053). Neighborhood affluence predicted lower levels of CBR (IRR=0.82, p<0.027), but neighborhood disadvantage was not significantly associated with CBR (IRR=1.00, p<0.948).
Neighborhood environments appear to play a pivotal role in the accumulation of biological risk and disparities therein.
social environment; health disparities; cumulative biological risk; allostatic load; risk factor
The sociology of aging draws on a broad array of theoretical perspectives from several disciplines, but rarely has it developed its own. We build on past work to advance and empirically test a model of mental health framed in terms of structural theorizing and situated within the life course perspective. Whereas most prior research has been based on cross-sectional data, we utilize four waves of data from a nationally representative sample of American adults (Americans' Changing Lives Study) collected prospectively over a 15-year period and find that education, employment and marital status, as well as their consequences for income and health, effectively explain the increase in depressive symptoms after age 65. We also found significant cohort differences in age trajectories of mental health that were partly explained by historical increases in education. We demonstrate that a purely structural theory can take us far in explaining later life mental health.
Many demographic, socioeconomic, and behavioral risk factors predict mortality in the United States. However, very few population-based longitudinal studies are able to investigate simultaneously the impact of a variety of social factors on mortality. We investigated the degree to which demographic characteristics, socioeconomic variables and major health risk factors were associated with mortality in a nationally-representative sample of 3,617 U.S. adults from 1986-2005, using data from the 4 waves of the Americans’ Changing Lives study. Cox proportional hazard models with time-varying covariates were employed to predict all-cause mortality verified through the National Death Index and death certificate review. The results revealed that low educational attainment was not associated with mortality when income and health risk behaviors were included in the model. The association of low-income with mortality remained after controlling for major behavioral risks. Compared to those in the “normal” weight category, neither overweight nor obesity was significantly associated with the risk of mortality. Among adults age 55 and older at baseline, the risk of mortality was actually reduced for those were overweight (hazard rate ratio=0.83, 95% C.I. = 0.71 – 0.98) and those who were obese (hazard rate ratio=0.68, 95% C.I. = 0.55 – 0.84), controlling for other health risk behaviors and health status. Having a low level of physical activity was a significant risk factor for mortality (hazard rate ratio=1.58, 95% C.I. = 1.20 – 2.07). The results from this national longitudinal study underscore the need for health policies and clinical interventions focusing on the social and behavioral determinants of health, with a particular focus on income security, smoking prevention/cessation, and physical activity.
Mortality; socioeconomic factors; health behavior; Unites States; obesity
This study examines whether the psychological traits of hopelessness and depressive symptoms are related to endothelial dysfunction.
Data come from a subsample of 434 respondents in the 2001–2003 Chicago Community Adult Health Study (CCAHS), a population-based survey designed to study the impact of psychological attributes, neighborhood environment, and socio-economic circumstances on adults age 18 and over. Circulating biomarkers of endothelial dysfunction including e-selectin, p-selectin and s-ICAM1 were obtained from serum samples. Hopelessness was measured by responses to two questions and depressive symptoms were measured by an 11-item version of the CES-D. Multivariate regression models tested whether continuous levels of the biomarkers (natural log transformed) were associated with levels of hopelessness and depressive symptoms separately and concurrently.
In age- and sex-adjusted models, hopelessness showed significant positive linear associations with s-ICAM1. In contrast, there was no significant linear association between hopelessness and e-selectin and p-selectin. Adjustment for clinical risk factors including systolic pressure, chronic health conditions, smoking, and body mass index did not substantively alter these associations. Results from similar models for depressive symptoms did not reveal any association with the three biomarkers of endothelial dysfunction. The associations between hopelessness and e-selectin and s-ICAM1 were robust to the inclusion of adjustments for depressive symptoms.
Negative psychosocial traits may influence cardiovascular outcomes partially through their impact on the early stages of atherosclerosis, and specific psychosocial traits such as hopelessness may play a more direct role in this process than overall depressive symptoms.
Social Security is the most important and effective income support program ever introduced in the United States, alleviating the burden of poverty for millions of elderly Americans. We explored the possible role of Social Security in reducing mortality among the elderly. In support of this hypothesis, we found that declines in mortality among the elderly exceeded those among younger age groups following the initial implementation of Social Security in 1940, and also in the periods following marked improvements in Social Security benefits via legislation and indexing of benefits that occurred between the mid-1960s and the early 1970s. A better understanding of the link between Social Security and health status among the elderly would add a significant and missing dimension to the public discourse over the future of Social Security, and the potential role of income support programs in reducing health-related socioeconomic disparities and improving population health.
Social Security; income support; social epidemiology; health policy
Studying the relation between the residential environment and health requires valid, reliable, and cost-effective methods to collect data on residential environments. This 2002 study compared the level of agreement between measures of the presence of neighborhood businesses drawn from 2 common sources of data used for research on the built environment and health: listings of businesses from commercial databases and direct observations of city blocks by raters. Kappa statistics were calculated for 6 types of businesses—drugstores, liquor stores, bars, convenience stores, restaurants, and grocers—located on 1,663 city blocks in Chicago, Illinois. Logistic regressions estimated whether disagreement between measurement methods was systematically correlated with the socioeconomic and demographic characteristics of neighborhoods. Levels of agreement between the 2 sources were relatively high, with significant (P < 0.001) kappa statistics for each business type ranging from 0.32 to 0.70. Most business types were more likely to be reported by direct observations than in the commercial database listings. Disagreement between the 2 sources was not significantly correlated with the socioeconomic and demographic characteristics of neighborhoods. Results suggest that researchers should have reasonable confidence using whichever method (or combination of methods) is most cost-effective and theoretically appropriate for their research design.
Chicago; geographic information systems; reproducibility of results; residence characteristics; social environment
We sought to demonstrate the advantages of using individual-level survey data in quantitative environmental justice analyses and to provide new evidence regarding racial and socioeconomic disparities in the distribution of polluting industrial facilities.
Addresses of respondents in the baseline sample of the Americans’ Changing Lives Study and polluting industrial facilities in the Environmental Protection Agency’s Toxic Release Inventory were geocoded, allowing assessments of distances between respondents’ homes and polluting facilities. The associations between race and other sociodemographic characteristics and living within 1 mile (1.6 km) of a polluting facility were estimated via logistic regression.
Blacks and respondents at lower educational levels and, to a lesser degree, lower income levels were significantly more likely to live within a mile of a polluting facility. Racial disparities were especially pronounced in metropolitan areas of the Midwest and West and in suburban areas of the South.
Our results add to the historical record demonstrating significant disparities in exposures to environmental hazards in the US population and provide a paradigm for studying changes over time in links to health.
Economic recessions, the industrial shift from manufacturing toward service industries, and rising global competition have contributed to uncertainty about job security, with potential consequences for workers’ health. To address limitations of prior research on the health consequences of perceived job insecurity, we use longitudinal data from two nationally-representative samples of the United States population, and examine episodic and persistent perceived job insecurity over periods of about three years to almost a decade. Results show that persistent perceived job insecurity is a significant and substantively important predictor of poorer self-rated health in the American’s Changing Lives (ACL) and Midlife in the United States (MIDUS) samples, and of depressive symptoms among ACL respondents. Job losses or unemployment episodes are associated with perceived job insecurity, but do not account for its association with health. Results are robust to controls for sociodemographic and job characteristics, negative reporting style, and earlier health and health behaviors.
USA; perceived job insecurity; self-rated health; depressive symptoms
Research on the effects of the built environment in the pathway from impairment to disability has been largely absent. Using data from the Chicago Community Adult Health Study (2001–2003), the authors examined the effect of built environment characteristics on mobility disability among adults aged 45 or more years (n = 1,195) according to their level of lower extremity physical impairment. Built environment characteristics were assessed by using systematic social observation to independently rate street and sidewalk quality in the block surrounding each respondent's residence in the city of Chicago (Illinois). Using multinomial logistic regression, the authors found that street conditions had no effect on outdoor mobility among adults with only mild or no physical impairment. However, among adults with more severe impairment in neuromuscular and movement-related functions, the difference in the odd ratios for reporting severe mobility disability was over four times greater when at least one street was in fair or poor condition (characterized by cracks, potholes, or broken curbs). When all streets were in good condition, the odds of reporting mobility disability were attenuated in those with lower extremity impairment. If street quality could be improved, even somewhat, for those adults at greatest risk for disability in outdoor mobility, the disablement process could be slowed or even reversed.
aging; lower extremity; mobility limitation; social environment; urban health
The spatial segregation of the U.S. population by socioeconomic position and especially race-ethnicity suggests that the social contexts or “neighborhoods” in which people live may substantially contribute to social disparities in hypertension. The Chicago Community Adult Health Study did face-to-face interviews, including direct measurement of blood pressure, with a representative probability sample of adults in Chicago. These data were used to estimate socioeconomic and racial-ethnic disparities in the prevalence, awareness, treatment, and control of hypertension, and to analyze how these disparities are related to the areas in which people live. Hypertension was significantly negatively associated with neighborhood affluence/gentrification, and adjustments for context eliminated the highly significant disparity between blacks/African-Americans and whites, and reduced the significant educational disparity by 10–15% to borderline statistical significance. Awareness of hypertension was significantly higher in more disadvantaged neighborhoods and in places with higher concentrations of blacks (and lower concentrations of Hispanics and immigrants). Adjustment for context completely eliminated blacks’ greater awareness, but slightly accentuated the lesser awareness of Hispanics and the greater levels of awareness among the less educated. There was no consistent evidence of either social disparities in or contextual associations with treatment of hypertension, given awareness. Among those on medication, blacks were only 40–50% as likely as whites to have their hypertension controlled, but context played little or no role in either the level of or disparities in control of hypertension. In sum, residential contexts potentially play a large role in accounting for racial-ethnic, and to a lesser degree, socioeconomic disparities in hypertension prevalence and, in a different way, awareness, but not in treatment or control of diagnosed hypertension.
Neighborhoods; social disparities; multi-level modeling; health inequalities; hypertension; blood pressure
The Healthy Environments Partnership (HEP) is a community-based participatory research effort investigating variations in cardiovascular disease risk, and the contributions of social and physical environments to those variations, among non-Hispanic black, non-Hispanic white, and Hispanic residents in three areas of Detroit, Michigan. Initiated in October 2000 as a part of the National Institute of Environmental Health Sciences’ Health Disparities Initiative, HEP is affiliated with the Detroit Community–Academic Urban Research Center. The study is guided by a conceptual model that considers race-based residential segregation and associated concentrations of poverty and wealth to be fundamental factors influencing multiple, more proximate predictors of cardiovascular risk. Within this model, physical and social environments are identified as intermediate factors that mediate relationships between fundamental factors and more proximate factors such as physical activity and dietary practices that ultimately influence anthropomorphic and physiologic indicators of cardiovascular risk. The study design and data collection methods were jointly developed and implemented by a research team based in community-based organizations, health service organizations, and academic institutions. These efforts include collecting and analyzing airborne particulate matter over a 3-year period; census and administrative data; neighborhood observation checklist data to assess aspects of the physical and social environment; household survey data including information on perceived stressors, access to social support, and health-related behaviors; and anthropometric, biomarker, and self-report data as indicators of cardiovascular health. Through these collaborative efforts, HEP seeks to contribute to an understanding of factors that contribute to racial and socioeconomic health inequities, and develop a foundation for efforts to eliminate these disparities in Detroit.
community-based participatory research partnerships; racial segregation and cardiovascular disease; social and physical environments and cardiovascular disease
Virus particles morphologically similar to caliciviruses and rotaviruses were detected by electron microscopy (EM) in the intestinal contents of a 27-day-old diarrheic nursing pig. A third small spherical 23-nm virus-like particle was also observed. Calicivirus-like particles averaged 33 nm in diameter. Similar to rotaviruses, rotavirus-like particles were present as single-capsid 55-nm forms or double-capsid 70-nm particles. Most gnotobiotic pigs orally exposed to samples containing these three viruses developed diarrhea and villous atrophy of the small intestine, and all shed the three viruses in their intestinal contents. Attempts to propagate these viruses in cell culture were unsuccessful. The antigenic relationship of the rotavirus-like particles to known rotaviruses was explored by immune EM and immunofluorescent staining. By these techniques, the rotavirus-like particles did not cross-react with antisera to porcine, bovine, or human rotaviruses or to reovirus type 3. Antisera from gnotobiotic pigs exposed to all three viruses had enzyme-linked immunosorbent assay and virus neutralization titers of <4 against porcine rotavirus. Previous infection of gnotobiotic pigs with the mixture containing rotavirus-like particles failed to protect them against a subsequent challenge with porcine rotavirus. The antigenic relationship of the calicivirus-like particles to known caliciviruses was investigated by immune EM and virus neutralization. By these tests, the calicivirus-like particles did not react with antisera against feline calicivirus strain 255 or M-8. In a study conducted at Plum Island Animal Disease Center, antiserum against the three combined agents did not specifically neutralize any serotype of swine vesicular exanthema virus.