James J. Quackenboss

Chronic respiratory effects of indoor formaldehyde exposure

The relation of chronic respiratory symptoms and pulmonary function to formaldehyde (HCHO) in homes was studied in a sample of 298 children (6-15 years of age) and 613 adults. HCHO measurements were made with passive samplers during two 1-week periods. Data on chronic cough and phlegm, wheeze, attacks of breathlessness, and doctor diagnoses of chronic bronchitis and asthma were collected with self-completed questionnaires. Peak expiratory flow rates (PEFR) were obtained during the evenings and mornings for up to 14 consecutive days for each individual. Significantly greater prevalence rates of asthma and chronic bronchitis were found in children from houses with HCHO levels 60-120 ppb than in those less exposed, especially in children also exposed to environmental tobacco smoke. In children, levels of PEFR decreased linearly with HCHO exposure, with the estimated decrease due to 60 ppb of HCHO equivalent to 22% of PEFR level in nonexposed children. The effects in asthmatic children exposed to HCHO below 50 ppb were greater than in healthy ones. The effects in adults were less evident: decrements in PEFR due to HCHO over 40 ppb were seen only in the morning, and mainly in smokers.

Indoor-outdoor relationships for particulate matter: Exposure classifications and health effects

Abstract As part of a study on the effects of indoor and outdoor air pollutants on respiratory health, measurements of indoor inhalable (PM 10 ) and respirable (PM 2.5 ) particulate matter have been collected in a sample of exposure-classified households. There was a close relationship between average indoor PM in these two size ranges, with a slope of 1.08 (PM 10 to PM 2.5 ), intercept of 12.5 μg/m 3 and R 2 of 88.6%. Samples collected in the same household during sequential weeks were generally closely related (R 2 of 85% for both sizes; difference was nonsignificant), although week-specific activities were important in explaining difference within some homes. The median indoor/outdoor (I/O) ratio was 0.63 for homes without reported smoking, and 1.1 for those with smoking. Corresponding mean indoor-outdoor differences were −3.6 and +13.5 μg/m 3 , which was only significant for homes with smoking (p 10 over 50 μg/m 3 was associated with non-specific (annoyance) symptoms. PM 2.5 over 15 μg/m 3 was related to symptoms of acute respiratory infections (depending on age group) and to daily variability in peak flow rates (independent of age and sex). These effects may be related to environmental tobacco smoke (ETS) exposures that are correlated with the measured PM concentrations, although more specific indicators of ETS are needed to confirm this.

Relation of peak expiratory flow rates and symptoms to ambient ozone

The temporal association between peak expiratory flow rates (PEFRs) and ambient ozone (O3) was studied in a group of 287 children and 523 nonsmoking adults in Tucson. In children, noon PEFRs were decreased on days when there was a higher O3 concentration; children with physician-confirmed asthma experienced the greatest decrease in noon PEFR. Evening PEFR levels were also significantly related to O3 in children, especially asthmatics. Among adults, evening PEFRs were decreased in asthmatics who spent more time outdoors on days when O3 levels were higher. After we adjusted for covariates, significant effects of interactions of 8-h O3 levels with particulate matter (PM10) and temperature on daily PEFR were found. There was some overnight effect of 8-h O3 on morning PEFRs. In general, the respiratory response to low-level ambient O3 is acute, occurs more in asthmatics, and increases as temperature and PM10 increase.

The epidemiological importance of intraindividual changes in objective pulmonary responses

Debate continues about what constitutes significant and meaningful change in health status of individuals and populations. More importantly, the basic biological and medical criteria that are used for clinical and environmental judgments require further discussion and clarification. What proportion of loss of cardio-pulmonary function, overt disability, or mortality is sufficient to determine an ≫ adverse health effect ≫? Health-oriented individuals, including researchers and clinicians, may choose to adhere to different criteria than other professional groups (e.g., legal, social). It is proposed in this paper that criteria for defining adverse health effects should represent clinically meaningful, as distinct from only statistically significant, responses. These include pulmonary function test results that indicate obstructive or restrictive diseases, and electrocardiogram results indicating coronary artery disease. Intraindividual changes that predict a meaningful medical change would be included; these changes should meet specific requirements in terms of what constitute normal vs. abnormal ranges of variation. Further, the proportion of the population defined to be impaired should be considered. These issues are the focus of this paper.

Epidemiological study of respiratory responses to indoor/outdoor air quality

Abstract Exposures to outdoor-type pollutants have been linked to indoor sources and exposures to indoor-specific pollutants also occur. The recognition of indoor air quality as a major component of total human exposure to air pollutants has raised serious questions about the adequacy of exposure assessment in previous air pollution health effects studies. Not only do outdoor pollutants penetrate indoors in the workplace or school and in the home, but these locations may also contain sources of air pollutants (i.e., nitrogen dioxide, suspended particulate matter, and formaldehyde). Thus, a study has been designed to evaluate respiratory responses to pollutant exposures from indoor and outdoor sources. Evaluation of interactions of measured pollutants and their effects on health is designed to be a major component of this study.

Multipollutant Exposures and Health Responses to Particulate Matter

Epidemiological methods provide opportunities to study interactions of pollutants in complex environments. During the study of health and the environment and the evaluation of particulate matter in Tucson, we found that type, location, and temporality of particulate matter exposures were critical with respect to the various interactions that related to health effects. Indoor particulate matter interacted with other components of particulate matter found in tobacco smoke, as evidenced by lung function. The interaction of environmental tobacco smoke with indoor formaldehyde caused various symptoms. Other interactions occurred between indoor and outdoor forms of particulate matter, which caused symptoms in some of the subjects.

An epidemiological approach investigating respiratory disease response in sensitive individuals to indoor and outdoor pollen exposure in Tucson, Arizona

SummaryWe conducted this study during the early spring to demonstrate direct response between increases in atmospheric pollen concentrations and symptom prevalence in a general population. We examined pollen concentrations indoors, outdoors and regionally in 31 households with similar background vegetation, pollen concentration, TSP and pollulant gas levels. Indoor pollen concentrations were low but persistent (X=16 grains/m3 air); local outdoor concentrations were 3 times greater. Regional daily mean pollen values of grasses, ragweed, mulberry and total pollen were compared with symptom scores using X2 contingency tests. We obtained daily symptom scores and measures of peak expiratory flow from 121 individuals characterized as «normal», «atopic» or «peak flow responsive». In atopic individuals, prevalence of nasal symptoms increased with pollen concentration increases for ragweed, mulberry and total pollen exposure. No significant response was found with spring grasses whose atmospheric pollen concentration was limited in the selected cluster. Decrease of lung function in the peak flow responsive population was found associated with mulberry pollen only. The small pollen grain size may result in greater tracheo-bronchial deposition.