Impact Of Ambient Pollution Research Articles

Impact of long-term exposure to ambient particulate matter and nitrogen dioxide on chronic obstructive pulmonary disease: results from the Women’s Health Initiative cohort

Abstract Rationale:
Although COPD prevalence and exacerbations have been linked to ambient pollutants, evidence on the impact of ambient pollutants on COPD incidence is relatively sparse.
Objectives:
To evaluate the associations of long-term ambient particulate matter (PM2.5; PM10), nitrogen dioxide (NO2), and incident self-reported COPD in the Women’s Health Initiative (WHI), a large prospective cohort study of post-menopausal women across the United States.
Methods:
We estimated annual average residential pollutant concentrations using validated spatiotemporal models and monitored data. We estimated pollutant-COPD associations as hazard ratios (HRs) and 95% confidence intervals (CI) per inter-quartile range (IQR) increase in pollutant using time-varying Cox proportional hazards models adjusted for potential confounders including sociodemographic characteristics, lifestyle and health factors, and WHI Clinical Center at baseline. Finally, we assessed the joint impact of exposure to multiple pollutants using quantile-based G-computation for survival outcomes.

Prenatal Nitrate Exposure and Childhood Asthma. Influence of Maternal Prenatal Stress and Fetal Sex.

Impact of ambient pollution upon children's asthma may differ by sex, and exposure dose and timing. Psychosocial stress can also modify pollutant effects. These associations have not been examined for in utero ambient nitrate exposure. We implemented Bayesian-distributed lag interaction models to identify sensitive prenatal windows for the influence of nitrate (NO3-) on child asthma, accounting for effect modification by sex and stress. Analyses included 752 mother-child dyads. Daily ambient NO3- exposure during pregnancy was derived using a hybrid chemical transport (Geos-Chem)/land-use regression model and natural log transformed. Prenatal maternal stress was indexed by a negative life events score (high [>2] vs. low [≤2]). The outcome was clinician-diagnosed asthma by age 6 years. Most mothers were Hispanic (54%) or black (29%), had a high school education or less (66%), never smoked (80%), and reported low prenatal stress (58%); 15% of children developed asthma. BDILMs adjusted for maternal age, race, education, prepregnancy obesity, atopy, and smoking status identified two sensitive windows (7-19 and 33-40 wk gestation), during which increased NO3- was associated with greater odds of asthma, specifically among boys born to mothers reporting high prenatal stress. Cumulative effects of NO3- across pregnancy were also significant in this subgroup (odds ratio = 2.64, 95% confidence interval = 1.27-5.39; per interquartile range increase in ln NO3-). Prenatal NO3- exposure during distinct sensitive windows was associated with incident asthma in boys concurrently exposed to high prenatal stress.

Methods for Measuring the Economic Impact of Ambient Pollutants on the Agricultural Sector: Discussion

ing from Pope, models for measuring economic impact should consider the follow- ing three principles: (a) it should be flexible enough to describe the underlying environ- ment; (b) it should accommodate theory; and (c) it should provide results that directly lead to policy implications. In this discussion these principles are employed as a criterion for judg- ing the merits of papers by Dixon, Garcia, and Mjelde (DGM); Hamilton, McCarl, and Adams (HMA); and Atkinson, Adams, and Crocker (AAC). A discussion of their papers is followed by suggestions for future research methods in measuring impacts of ambient pol- lutants.

Methods for Measuring the Economic Impact of Ambient Pollutants on the Agricultural Sector: Discussion

The author faults three papers showing alternative methods of measuring the impacts of ozone on crop yields (which progress from experimental test plot to farm-level profits to aggregate welfare implications) for not informing the reader on the importance of the problem. In analyzing the results of four models, he concludes that we have discovered that tropospheric ozone tends to reduce soybean yields more than corn yields, and that the welfare gains from reducing the ozone concentration 25% in the Corn Belt is only about $650 million, or less than 4% of total net farm income for the US. What the papers fail to tell is the total cost to society of reducing the concentrations of ozone and the overall benefit cost ratio. 3 references.