Although a very small effect cannot be excluded, there was no consistent association between ambient levels of fine-particulate matter and risk of MI onset.

Ambient air pollutant exposure has been linked to childhood respiratory disease, but infants have received little study. The authors tested the hypotheses that subchronic and chronic exposure to fine particulate matter (particulate matter < or = 2.5 microm in aerodynamic diameter (PM2.5)), nitrogen dioxide, carbon monoxide, and ozone increases risk of severe infant bronchiolitis requiring hospitalization. Study subjects were derived from linked birth-hospital-discharge records of infants born in 1995-2000 in the South Coast Air Basin of California. Cases with a hospital discharge for bronchiolitis in infancy were matched to 10 age- and gestational-age-matched controls. Exposures in the month prior to hospitalization (subchronic) and mean lifetime exposure (chronic) referenced to the case diagnosis date were assessed on the basis of data derived from the California Air Resources Board. In conditional logistic regression, only subchronic and chronic PM2.5 exposures were associated with increased risk of bronchiolitis hospitalization after adjustment for confounders (per 10-microg/m3 increase, adjusted odds ratio = 1.09 (95% confidence interval: 1.04, 1.14) for both). Ozone was associated with reduced risk in the single-pollutant model, but this relation did not persist in multipollutant models including PM2.5. These unique US data suggest that infant bronchiolitis may be added to the list of adverse effects of PM2.5 exposure.

Background: Short term increases in exposure to particulate matter (PM) air pollution are associated with increased cardiovascular morbidity and mortality. The mechanism behind this effect is unclear, although changes in autonomic control have been observed. It was hypothesised that increases in fine PM measured at the subjects' home in the preceding hour would be associated with decreased high frequency heart rate variability (HF-HRV) in individuals with pre-existing cardiac disease. Methods: Two hundred and eighty five daily 20 minute measures of HRV (including a paced breathing protocol) were made in the homes of 34 elderly individuals with (n = 21) and without (n = 13) cardiovascular disease (CVD) over a 10 day period in Seattle between February 2000 and March 2002. Fine PM was continuously measured by nephelometry at the individuals' homes. Results: The median age of the study population was 77 years (range 57-87) and 44% were male. Models that adjusted for health status, relative humidity, temperature, mean heart rate, and medication use did not find a significant association between a 10 mg/m 3 increase in 1 hour mean outdoor PM 2.5 before the HRV measurement and a change in HF-HRV power in individuals with CVD (3% increase in median HF-HRV (95% CI 219 to 32)) or without CVD (5% decrease in median HF-HRV (95% CI 234 to 36)). Similarly, no association was evident using 4 hour and 24 hour mean outdoor PM 2.5 exposures before the HRV measurement. Conclusion: No association was found between increased residence levels of fine PM and frequency domain measures of HRV in elderly individuals.

Although multifactorial fall prevention interventions have been shown to reduce falls and injurious falls, their translation into clinical settings has been limited. This article describes a hospital-based fall prevention clinic established to increase availability of preventive care for falls. Outcomes for 43 adults aged 65 and older seen during the clinic's first 6 months of operation were compared with outcomes for 86 age-, sex-, and race-matched controls; all persons included in analyses received primary care at the hospital's geriatrics clinic. Nonsignificant differences in falls, injurious falls, and fall-related healthcare use according to study group in multivariate adjusted models were observed, probably because of the small, fixed sample size. The percentage experiencing any injurious falls during the follow-up period was comparable for fall clinic visitors and controls (14% vs 13%), despite a dramatic difference at baseline (42% of clinic visitors vs 15% of controls). Fallrelated healthcare use was higher for clinic visitors during the baseline period (21%, vs 12% for controls) and decreased slightly (to 19%) during follow-up; differences in fall-related healthcare use according to study group from baseline to follow-up were nonsignificant. These findings, although preliminary because of the small sample size and the baseline difference between the groups in fall rates, suggest that being seen in a fall prevention clinic may reduce injurious falls. Additional studies will be necessary to conclusively determine the effects of multifactorial fall risk assessment and management delivered by midlevel providers working in real-world clinical practice settings on key outcomes, including injurious falls, downstream fall-related healthcare use, and costs.

Three multivariate receptor algorithms were applied to seven years of chemical speciation data to apportion fine particulate matter to various sources in Spokane, Washington. Source marker compounds were used to assess the associations between atmospheric concentration of these compounds and daily cardiac hospital admissions and/or respiratory emergency department visits. Total carbon and arsenic had high correlations with two different vegetative burning sources and were selected as vegetative burning markers, while zinc and silicon were selected as markers for the motor vehicle and airborne soil sources, respectively. The rate of respiratory emergency department visits increased 2% for a 3.0 microg/m3 interquartile range change in a vegetative burning source marker (1.023, 95% CI 1.009-1.038) at a lag of one day. The other source markers studied were not associated with the health outcomes investigated. Results suggest vegetative burning is associated with acute respiratory events.