BackgroundResearch has shown associations between pediatric asthma outcomes and airborne particulate matter (PM). The importance of particle components remains to be determined.MethodsWe followed a panel of 45 schoolchildren with persistent asthma living in Southern California. Subjects were monitored over 10 days with offline fractional exhaled nitric oxide (FeNO), a biomarker of airway inflammation. Personal active sampler exposures included continuous particulate matter < 2.5 μm in aerodynamic diameter (PM2.5), 24-hr PM2.5 elemental and organic carbon (EC, OC), and 24-hr nitrogen dioxide. Ambient exposures included PM2.5, PM2.5 EC and OC, and NO2. Data were analyzed with mixed models controlling for personal temperature, humidity and 10-day period.ResultsThe strongest positive associations were between FeNO and 2-day average pollutant concentrations. Per interquartile range pollutant increase, these were: for 24 μg/m3 personal PM2.5, 1.1 ppb FeNO [95% confidence interval (CI), 0.1–1.9]; for 0.6 μg/m3 personal EC, 0.7 ppb FeNO (95% CI, 0.3–1.1); for 17 ppb personal NO2, 1.6 ppb FeNO (95% CI, 0.4–2.8). Larger associations were found for ambient EC and smaller associations for ambient NO2. Ambient PM2.5 and personal and ambient OC were significant only in subjects taking inhaled corticosteroids (ICS) alone. Subjects taking both ICS and antileukotrienes showed no significant associations. Distributed lag models showed personal PM2.5 in the preceding 5 hr was associated with FeNO. In two-pollutant models, the most robust associations were for personal and ambient EC and NO2, and for personal but not ambient PM2.5.ConclusionPM associations with airway inflammation in asthmatics may be missed using ambient particle mass, which may not sufficiently represent causal pollutant components from fossil fuel combustion.

Chronic kidney disease is associated with a higher risk for cardiovascular mortality, as well as all-cause mortality. Whether chronic kidney disease is a predictor of noncardiovascular mortality is less clear. To further explore the latter, the association of kidney function with total noncardiovascular mortality and cause-specific mortality was assessed in the Cardiovascular Health Study, a community-based cohort of older individuals. Kidney disease was assessed using cystatin C and estimated GFR in 4637 participants in 1992 to 1993. Participants were followed until June 30, 2001. Deaths were adjudicated as cardiovascular or noncardiovascular disease by committee, and an underlying cause of death was assigned. The associations of kidney function with total noncardiovascular mortality and cause-specific mortality were analyzed by proportional hazards regression. Noncardiovascular mortality rates increased with higher cystatin C quartiles (16.8, 17.1, 21.6, and 50.0 per 1000 person-years). The association of cystatin C with noncardiovascular mortality persisted after adjustment for demographic factors; the presence of diabetes, C-reactive protein, hemoglobin, and prevalent cardiovascular disease; and measures of atherosclerosis (hazard ratio 1.69; 95% confidence interval 1.33 to 2.15, for the fourth quartile versus the first quartile). Results for estimated GFR were similar. The risk for noncardiac deaths attributed to pulmonary disease, infection, cancer, and other causes was similarly associated with cystatin C levels. Kidney function predicts noncardiovascular mortality from multiple causes in the elderly. Further research is needed to understand the mechanisms and evaluate interventions to reduce the high mortality rate in chronic kidney disease.

BackgroundEpidemiologic studies have shown associations between asthma outcomes and outdoor air pollutants such as nitrogen dioxide and particulate matter mass < 2.5 μm in diameter (PM2.5). Independent effects of specific pollutants have been difficult to detect because most studies have relied on highly correlated central-site measurements.ObjectivesThis study was designed to evaluate the relationship of daily changes in percent-predicted forced expiratory volume in 1 sec (FEV1) with personal and ambient air pollutant exposures.MethodsFor 10 days each, we followed 53 subjects with asthma who were 9–18 years of age and living in the Los Angeles, California, air basin. Subjects self-administered home spirometry in themorning, afternoon, and evening. We measured personal hourly PM2.5 mass, 24-hr PM2.5 elemental and organic carbon (EC–OC), and 24-hr NO2, and the same 24-hr average outdoor central-site(ambient) exposures. We analyzed data with transitional mixed models controlling for personal temperature and humidity, and as-needed β2-agonist inhaler use.ResultsFEV1 decrements were significantly associated with increasing hourly peak and daily average personal PM2.5, but not ambient PM2.5. Personal NO2 was also inversely associated with FEV1. Ambient NO2 was more weakly associated. We found stronger associations among 37 subjects not taking controller bronchodilators as follows: Personal EC–OC was inversely associated with morning FEV1; for an interquartile increase of 71 μg/m3 1-hr maximum personal PM2.5, overall percent-predicted FEV1 decreased by 1.32% [95% confidence interval (CI), −2.00 to −0.65%]; and for an interquartile increase of 16.8 ppb 2-day average personal NO2, overall percent-predicted FEV1 decreased by 2.45% (95% CI, −3.57 to −1.33%). Associations of both personal PM2.5 and NO2 with FEV1 remained when co-regressed, and both confounded ambient NO2.ConclusionsIndependent pollutant associations with lung function might be missed using ambient data alone. Different sets of causal components are suggested by independence of FEV1 associations with personal PM2.5 mass from associations with personal NO2.

In spite of growing interest, a principal obstacle to wider inclusion of improved cookstove projects in carbon trading schemes has been the lack of accountability in estimating CO 2 -equivalent (CO 2 -e) savings. To demonstrate that robust estimates of CO 2 -e savings can be obtained at reasonable cost, an integrated approach of community-based subsampling of traditional and improved stoves in homes to estimate fuel consumption and greenhouse gas emissions, combined with spatially explicit community-based estimates of the fraction of nonrenewable biomass harvesting (fNRB), was used to estimate CO 2 -e savings for 603 homes with improved Patsari stoves in Purépecha communities of Michoacán, Mexico. Mean annual household CO 2 -e savings for CO 2 , CH 4 , CO, and nonmethane hydrocarbons were 3.9 tCO 2 -e home -1 yr -1 (95% CI ( 22%), and for Kyoto gases (CO 2 and CH 4 ) were 3.1 tCO 2 -e home -1 yr -1 (95% CI ( 26%), respectively, using a weighted mean fNRB harvesting of 39%. CO 2 -e savings ranged from 1.6 (95% CI ( 49%) to 7.5 (95% CI ( 17%) tCO 2 -e home -1 yr -1 for renewable and nonrenewable harvesting in individual communities, respectively. Since emission factors, fuel consumption, and fNRB each contribute significantly to the overall uncertainty in estimates of CO 2 -e savings, communitybased assessment of all of these parameters is critical for robust estimates. Reporting overall uncertainty in the CO 2 -e savings estimates provides a mechanism for valuation of carbon offsets, which would promote better accounting that CO 2 -e savings had actually been achieved. Cost of CO 2 -e savings as a result of adoption of Patsari stoves was US$8 per tCO 2 -e based on initial stove costs, monitoring costs, and conservative stove adoption rates, which is ∼4 times less expensive than use of carbon capture and storage from coal plants, and ∼18 times less than solar power. The low relative cost of CO 2 -e abatement of improved stoves combined with substantial health cobenefits through reduction in indoor air pollution provides a strong rationale for targeting these less expensive carbon mitigation options, while providing substantial economic assistance for stove dissemination efforts. IntroductionThere is growing interest in trading carbon offsets from improved stove programs on carbon markets for voluntary reductions, or as part of the Clean Development Mechanism (CDM) of the Kyoto Protocol. This interest arises from the large number of people that still cook with biomass (approximately half of the global population) (1), and because emissions of greenhouse gases (GHGs) relative to delivered energy are high as a result of poor total energy efficiency of traditional stoves. There are three principal barriers to more widespread acceptance of carbon offsets from improved biomass cookstove projects. First, measurement and verification of emissions reductions are complex compared to the stack monitors typically used for industrial facilities, as stoves are spread over large areas, often in remote regions. Traditional assess...

A long-term intervention (2.69 years) with an antioxidant diet, behavioral enrichment, or the combined treatment preserved and improved cognitive function in aged canines. While each intervention alone provided cognitive benefits, the combination treatment was additive. We evaluate the hypothesis that antioxidants, enrichment, or the combination intervention reduces age-related beta-amyloid (Aβ) neuropathology, as one mechanism mediating observed functional improvements. Measures assessed were Aβ neuropathology in plaques, biochemically extractable Aβ40 and Aβ42 species, soluble oligomeric forms of Aβ, and various proteins in the beta-amyloid precursor protein (APP) processing pathway. The strongest and most consistent effects on Aβ pathology were observed in animals receiving the combined antioxidant and enrichment treatment. Specifically, Aβ plaque load was significantly decreased in several brain regions, soluble Aβ42 was decreased selectively in the frontal cortex, and a trend for lower Aβ oligomer levels was found in the parietal cortex. Reductions in Aβ may be related to shifted APP processing towards the non-amyloidogenic pathway, as alpha-secretase enzymatic activity was increased, in the absence of changes in beta-secretase activity. While enrichment alone had no significant effects on Aβ, reduced Aβ load and plaque maturation occurred in animals receiving antioxidants as a component of treatment. AB measures did not correlate with cognitive performance on any of the 6 tasks assessed, suggesting that modulation of AB alone may be a relatively minor mechanism mediating cognitive benefits of the interventions. Overall, the data indicate that multi-domain treatments may be a valuable intervention strategy to reduce neuropathology and improve cognitive function in humans.