Status and determinants of individual actions to reduce health impacts of air pollution in US adults.

Although regulation of emissions is the primary strategy to reduce air pollution-related morbidity, individual-level interventions are also helpful in mitigating health impacts. We used data from 2007-2008 National Health and Nutrition Examination Survey to study the prevalence of individual-level action among the US adult population if informed of air pollution, and to see if this differed by demographic and health factors. Only 13.5% (95% confidence interval [CI]: 11.6-15.4%) of participants aware of air quality reported changing their individual behaviors. Males (adjusted odds ratio [AOR]: 0.66, 95% CI: 0.56-0.77) and those without cardiovascular disease (AOR: 0.58, 95% CI: 0.47-0.71) were least likely to take action. Results show that individual action was infrequent among the population. Health promotion of individual intervention is necessary, and this effort may need to target specific subgroups of the population. Further studies on effective individual interventions are needed.

Racial Differences in Age-Related Variations of Testosterone Levels Among US Males: Potential Implications for Prostate Cancer and Personalized Medication.

AIM: The magnitude of the age-related declines in testosterone rather than levels measured at single point in time may be related to the genesis of prostate cancer (PCa). We examined age-related variations of testosterone levels among black and white males, which may provide important insights into racial disparities in PCa incidence and mortality. METHOD: We analyzed data from the 1999-2004 National Health and Nutritional Examination Survey to compare age-related variations in the testosterone levels of 355 black and 631 white males. RESULT: Overall, between the ages of 12 and 15, black males had lower testosterone levels than white males. Testosterone levels increased rapidly with age and reached higher and earlier peak levels in black males compared to white males at 20-30 years of age. After reaching a peak level, testosterone levels declined earlier in blacks than in whites. Further analyses showed that black males had considerably higher levels of testosterone compared to white males aged 20-39 years after adjusting for covariates, including age, body mass index, cigarette smoking, physical activity, and waist circumference; however, no statistically significant differences were observed between the groups at any other age. CONCLUSION: Our study revealed that testosterone levels in black males decrease substantially with increasing age compared to those in white males. This rapid drop in testosterone levels may contribute to racial disparities in PCa. Our findings also suggest that personalized medication for hormone replacement therapy may be necessary to avoid sudden drops in testosterone levels, particularly for black males.

Health effects of air pollution on length of respiratory cancer survival.

BACKGROUND: Air pollution has been extensively and consistently linked with mortality. However, no study has investigated the health effects of air pollution on length of survival among diagnosed respiratory cancer patients. METHODS: In this study, we conducted a population-based study to investigate if air pollution exposure has adverse effects on survival time of respiratory cancer cases in Los Angeles (LA), CA and Honolulu, HI. We selected all White respiratory cancer patients in the two study areas from the 1992-2008 Surveillance Epidemiology and End Results cancer data. Death from respiratory cancer and length of survival were the main outcomes. RESULTS: Kaplan-Meier survival analysis shows that all respiratory cancer cases exposed to high air pollution referring to the individuals from LA had a significantly shorter survival time than the low pollution exposure group referring to those from Honolulu without adjusting for other covariates (p <0.0001). Moreover, the results from the Cox Proportional-Hazards models suggest that exposure to particles less than 10 micrometers in diameter (PM10) was associated with an increased risk of cancer death (HR = 1.48, 95% CI: 1.44-1.52 per 10 µg/m3 increase in PM10) after adjusting for demographic factors and cancer characteristics. Similar results were observed for particles less than 2.5 micrometers in diameter and ozone. CONCLUSION: Our study indicates that air pollution may have deleterious effects on the length of survival among White respiratory cancer patients. This study calls for attention to preventive effort from air pollution for this susceptible population in standard cancer patient care. The findings from this study warrant further investigation.

Association between ozone exposure and onset of stroke in Allegheny County, Pennsylvania, USA, 1994-2000.

BACKGROUND: Epidemiological studies have shown adverse short-term effects of air pollution on health including cardiovascular morbidity and mortality. However, air pollution-related stroke has received less attention. METHODS: In this study, we performed a time-stratified case-crossover analysis to evaluate the relationships between stroke hospital admissions and O3, among patients aged 65 years and older in Allegheny County, Pa., USA, between 1994 and 2000. We also examined whether the effects of air pollutants differed across strata defined by patient demographic characteristics and ambient temperature. RESULTS: Exposures to O3 on the current day increase the risk of total stroke hospitalization by 1.9% (95% CI: 0.01-3.8) per interquartile range increase in concentration. Furthermore, the results suggest that males were more sensitive to adverse health effects of O3 on stroke hospitalization than females. CONCLUSION: These results suggest that O3 has an adverse effect on stroke hospitalization. Specific patient subgroups, such as males, may be at increased risk.