Passive smoking and adults: new evidence for adverse effects.
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Adult↗
Biomedical subjects
B P Leaderer
Publications and source records attributed to B P Leaderer.
Reduction of environmental tobacco smoke exposure among asthmatic children: a controlled trial.
STUDY OBJECTIVE: This randomized clinical trial tested a behavioral medicine program designed to reduce asthmatic children's exposure to environmental tobacco smoke (ETS) in the home. DESIGN: Families were randomly assigned to an experimental preventive medicine counseling group, a monitoring control group, or a usual treatment control group. Families were measured six times over 1 year. PARTICIPANTS: Ninety-one families were recruited from four allergy clinics. INTERVENTION: The experimental group received a 6-month series of counseling sessions designed to decrease ETS exposure. This group also monitored smoking, exposure, and children's asthma symptoms. The monitoring group did not receive counseling and the usual treatment control group received outcome measures only. MEASUREMENTS AND RESULTS: Parents reported the daily number of cigarettes children were exposed to during the week preceding interviews. A nicotine air monitor and construct validity analysis confirmed the validity of exposure reports. Exposure to the parent's cigarettes in the home decreased for all groups. The experimental group attained a 79 percent decrease in children's ETS exposure, compared with 42 percent for the monitoring control and 34 percent for the usual treatment control group. Repeated-measures analysis of variance resulted in a significant (F([10,350] = 1.92, p < 0.05) group by time effect. At the final 12-month visit, the experimental/counseling group sustained a 51% decrease in children's exposure to cigarettes in the home from all smokers, while the monitoring control group showed an 18% decrease and the usual treatment control group a 15% decrease from pre-intervention [corrected]. CONCLUSION: A behavioral medicine program was successful in reducing exposure to ETS in the home for these asthmatic children.
Adolescent↗
Assessing exposures to inhaled complex mixtures.
In the course of daily activities, individuals spend varying amounts of time in different spaces where they are exposed to a complex mixture of gas, vapor, and particulate contaminants. The term complex is used in this paper to refer to binary mixtures as well as truly complex mixtures of three or more constituents. The diversity of the environments where pollution may occur, the number of pollutants that may be present, and the nature of the activity in the environment combine to pose a challenge to investigators of the health effects of air pollutants. This article discusses several methods of measuring or assessing exposure to complex mixture air contaminants that include time-activity assessments, personal monitoring, biomarkers of exposure, and microenvironmental models that can be employed singly or in combination in a protocol for exposure assessment. The use of nested designs, involving more intensive data collection from samples or subjects, is also considered.
Air Pollutants↗
Indoor exposures to fine aerosols and acid gases.
Indoor exposures to aerosols and gases are associated with both indoor and outdoor air pollution sources. The identification of sources and the assessment of their relative contribution can be a complicated process due to a) the presence of numerous indoor sources, which can vary from building to building; b) the uncertainties associated with the estimation of the impact of outdoor sources on indoor air quality; c) the interactions between pollutants; and d) the importance of reactions between pollutants and indoor surfaces. It is well established that fine particles (diameter less than or equal to 2.5 microns) originating from outdoor sources such as automobiles, oil and coal combustion, incineration, and diverse industrial activities can penetrate into the indoor environment. Indoor/outdoor ratios, usually varying between 0.4 and 0.8, depend on parameters such as particle size and density, air exchange rate, and the surface-to-volume ratio of the indoor environment. Determining fine particle elemental composition makes it possible to identify the contribution of different outdoor sources. This paper focuses on the origin and the concentration of indoor aerosols and acid gases by highlighting the results from two indoor air quality studies.
Aerosols↗
Assessing exposures to environmental tobacco smoke.
The combustion of tobacco indoors results in the emission of a wide range of air contaminants that are associated with a variety of acute and chronic health and comfort effects. Exposures to environmental tobacco smoke (ETS) are assessed for epidemiologic studies and risk assessment and risk management applications. An individual's or population's exposure to ETS can be assessed by direct methods, which employ personal air monitoring and biomarkers, and indirect methods, which utilize various degrees of microenvironmental measurements of spaces, models, and questionnaires in combination with time-activity information. The major issues related to assessing exposures to ETS are summarized and discussed, including the physical-chemical nature of ETS air contaminants, use of proxy air contaminants to represent ETS, use of biomarkers, models for estimating ETS concentrations indoors, and the application of questionnaires.
Biomarkers↗
Markers of exposure to diesel exhaust and cigarette smoke in railroad workers.
Diesel exhaust is a complex mixture of combustion gases, vapors and particles, and personal exposure can be estimated indirectly only. Quantitative estimates of exposure were developed for thirteen job groups in a large epidemiologic study of mortality among railroad workers. Three possible markers of exhaust exposure were developed. The first index was the concentration of respirable particles because this was simple and inexpensive to measure precisely. Major positive interference, however, was found from environmental tobacco smoke (ETS) and inorganic respirable particles from other emission sources. Composited job group samples were analyzed for particulate nicotine so the ETS component could be subtracted from the respirable particle concentration. This produced a second exposure index, the adjusted respirable particle concentrations. Since there are nondiesel sources of particles in some work areas, a third marker was sought. Diesel exhaust particles have a relatively high content of dichloromethane extractable matter, but inorganic particles have a low extractable content. Therefore, the air concentration of extractable mass was used as a third marker of diesel exposures. The extractable matter also was corrected for the contribution of ETS. The advantages and limitations of these three markers are of interest. In general, considerable caution should be used in the development and application of markers; their use requires detailed knowledge of the nature and sources of exposure in a given setting.
Air Pollutants, Occupational↗
Air pollution and health.
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Air Pollution↗
A study of respiratory effects from exposure to 2.0 ppm formaldehyde in occupationally exposed workers.
It has been suggested that exposure to formaldehyde (FA) induces asthmatic symptomatology. We have previously studied healthy and asthmatic individuals and found that lung function was unaltered by controlled exposures to 2.0 ppm FA with and without mild exercise. Our present study extends these observations to a group of hospital laboratory workers routinely exposed to FA. Fifteen laboratory workers were exposed in double-blind, random sequence to 0 and 2 ppm FA for 40 min in an environmental chamber with temperature and relative humidity held constant at 23 degrees C and 50%, respectively. These exposures were repeated on two more occasions with a 10-min exercise regimen (450 kpm/min) after being in the chamber 5 min. In addition, a symptom diary and measurements of peak expiratory flow rate (PEFR) were recorded for 24 hr after exposure. Lung function remained unaltered for all 4 exposure days; e.g., mean FEV1.0 for the group did not change by more than 3% at any testing time on any exposure day. Also, there were no delayed obstructive changes as measured by PEFR recordings. Symptoms were mild and transient with unusual odor and eye irritation the most frequent complaint. No lower airway symptoms were reported. We conclude that this group of healthy laboratory workers did not experience any acute or delayed lung function changes from exposure to 2.0 ppm FA at rest and with exercise and that irritative symptoms were few.
Adult↗
Odorization of inert gas for occupational safety: psychophysical considerations.
Odorization of inert gas can serve to warn workers in an enclosed space about gas leaking into the space. This psychophysical investigation, performed under conditions of directed attention, examined two candidates for possible odorization of argon:pyridine and cis-3-hexen-1-ol. Detection thresholds for pyridine and cis-3-hexen-1-ol in argon were 106 ppb and 19 ppb, respectively. Practice over four days yielded modest improvement in the detection of both odorants. For cis-3-hexen-1-ol, smokers had marginally lower thresholds than nonsmokers and older participants had slightly higher thresholds than younger participants. Gender, smoking status and age had no reliable influence on threshold for pyridine. This outcome indicated desirable perceptual stability for pyridine. Additional experiments dealt with the perceived intensity of pyridine and cis-3-hexen-1-ol over time in the realistic setting of an environmental chamber. Visitors to the chamber and occupants in the chamber assessed perceived magnitude at 5-min intervals for up to 60 min during injections of odorized argon into the chamber. Participants could gauge and track the concentration of pyridine much better than that of cis-3-hexen-1-ol. This held true for occupants almost to the same degree as visitors, though occupants inevitably exhibited some olfactory adaptation. Hence, the suprathreshold measurements also gave strong relative endorsement to pyridine. Calculations based on the experimental results indicated that odorization of the inert gas stream with 3 to 10 ppm (v/v) pyridine should suffice to warn occupants or visitors of an argon buildup of any severity. Field studies should permit a definitive judgment of the best concentration to use in practice.
Adult↗
Assessment of exposure to indoor air contaminants from combustion sources: methodology and application.
A methodology for assessing indoor air pollutant exposures is presented, with specific application to unvented combustion by-products. This paper describes the method as applied to a study of acute respiratory illness associated with the use of unvented kerosene space heaters in 333 residences in the New Haven, Connecticut, area from September 1982 to April 1983. The protocol serves as a prototype for a nested design of exposure assessment which could be applied to large-scale field studies of indoor air contaminant levels. Questionnaires, secondary records, and several methods of air monitoring offer a reliable method of estimating environmental exposures for assessing associations with health effects at a reasonable cost. Indoor to outdoor ratios of NO2 concentrations were found to be 0.58 +/- 0.31 for residences without known sources of NO2. Levels of NO2 were found to be comparable for homes with a kerosene heater only and those with a gas cooking stove only. Homes with a kerosene heater and a gas stove had average two-week NO2 levels approximately double those with only one source. Presence of tobacco smokers had a small but significant impact on indoor NO2 levels. Two-week average levels of indoor NO2 were found to be excellent predictors of total personal NO2 exposure for a small sample of adults. Residences with kerosene space heaters had SO2 levels corresponding to the number of hours of heater use and the sulfur content of the fuel. Formaldehyde levels were found to be low and not related to unvented combustion sources. NO2, SO2, and CO2 levels measured in some of the residences were found to exceed those levels specified in current national health standards.
Air Pollutants↗
Respiratory symptoms associated with sulfur dioxide exposure.
Exposures to sulfur dioxide (SO2) have been associated with progressive, dose-dependent bronchoconstriction in sensitive individuals. The clinical significance of such changes remains poorly characterized. We studied subjective responses following exposure to low level concentrations of SO2 (less than 1 ppm) in a group of 10 healthy and 10 asthmatic subjects. The number and severity of complaints associated with SO2 increased with concentrations in both healthy and asthmatic subjects. Asthmatics indicated progressive lower respiratory complaints, such as wheezing, chest tightness, dyspnea and cough with increasing levels of SO2 while healthy subjects complained more frequently of upper airway complaints such as taste and odor with increasing levels of SO2. Exercise increased the frequency of lower airway symptoms in asthmatics but led to no increases in symptoms in healthy subjects.
Adult↗
Stability of tobacco smoke odor in enclosed spaces.
During each of five experiments, four sedentary subjects smoked a total of 8 cigarettes during one hour while occupying an odor test chamber. The air temperature was 20-22 degrees C and the relative humidity was 35-50%. During the entire test period (6 h) the odor intensity in the chamber was evaluated by judges. After smoking ceased, the odor intensity continued to rise for one or two hours and then remained constant in a way that is characteristic of unreactive contaminants.
Climate↗
Ambient sulfates, photochemical oxidants, and acute adverse health effects: an epidemiological study.
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Adult↗
Summary of the New York Summer Aerosol Study (NYSAS).
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Aerosols↗
Comparisons of seasonal fungal prevalence in indoor and outdoor air and in house dusts of dwellings in one Northeast American county.
Fungi cause allergies and many other adverse health effects. In this study, we characterized the nature and seasonal variation of fungi inside and outside homes in the Greater New Haven, Connecticut area. Three indoor air samples (in the living room, bedroom, and basement) and one outdoor sample were collected by the Burkard portable air sampler. House dust samples were collected in the living room by a vacuum cleaner. The mold concentrations varied widely from house to house in both indoor and outdoor air. No significant difference (p>0.05) in concentration and type of fungi between living room and bedroom or by season was observed. Both concentration and type of fungi were significantly higher (p<0.05) in the basement than other indoor areas and outdoor air in winter. The type of fungi in living room, bedroom, and outdoor air were found to have significant changes among seasons, but there was no significant difference for the basement among seasons. Cladosporium spp. was dominant in both indoor and outdoor air in summer. Penicillium and Aspergillus were dominant in indoor air in winter, but neither was dominant in any season in outdoor air. The type of fungi and their concentrations in house dust samples were not representative of those isolated in indoor air. In dust samples, more Mucor, Wallemia, and Alternaria species, but less Aspergillus, Cladosporium, and Penicillium species were found in all seasons. Air sampling in spring or fall in every suspected house is suggested for year-round fungal exposure assessment.
Air Microbiology↗
Indoor and outdoor PM2.5 and CO in high- and low-density Guatemalan villages.
Continuous particles less than 2.5 microm in diameter (PM2.5) and carbon monoxide (CO) were monitored during breakfast, lunch, and dinner in three high-density and four low-density villages near Quetzaltenango, Guatemala to help assess the viability of this region for a proposed respiratory health and stove intervention study. Approximately 15 homes were visited during each mealtime in each of the seven villages; in all, 98 homes were visited, with a sampling duration of 2-3 min per home per meal. For each village, a line (transect) was drawn on a village map along existing roads from one end of the village to the other; homes and between-home outside locations along the transect were monitored. Although the predominant stove type was the open fire, several other stoves, in various levels of disrepair, were observed frequently. The highest indoor concentrations of PM2.5 were observed in homes using the open fire (avg. = 5.31 mg/m3; SD=4.75 mg/m3) or equivalent, although homes using the plancha--indigenous wood-burning stove with chimney--also had measurements > 13.8 mg/m3, PM2.5 limit of detection. The highest indoor concentrations of CO were also observed in homes using the open fire (avg. = 22.9 ppm; SD = 28.1 ppm), with a maximum measurement of > 250 ppm. For both PM2.5 and CO, levels measured in homes with plancha, lorena, or open fire were significantly higher than levels taken in the street or in homes using a gas stove. The Spearman correlation coefficient between PM2.5 and CO for all data combined was 0.81, and ranged from 0.30 for the lorena to 0.68 for the plancha in homes using wood-fueled stoves. Although indoor PM2.5 and CO levels were not significantly different between high- and low-density villages, street-level PM2.5 (p = 0.002) and CO (p= 0.002), were significantly higher in the high - density villages. These data provide a useful picture of the pollution levels coming from a range of cooking stoves in various levels ofdisrepair, as well as a representation of how outdoor particle mass and CO levels vary from high- versus low-density villages.
Air Pollution, Indoor↗
Airway effects of low concentrations of sulfur dioxide: dose-response characteristics.
The acute respiratory effects of exposure to low-level, short-term sulfur dioxide (SO2) were studied in ten asthmatic and ten healthy subjects. Subjects were exposed in an environmental chamber in a double-blind, random sequence to SO2) levels of 0.00, 0.25, 0.50, 0.75, and 1.00 ppm for 40 min. During the first 10 min subjects exercised on a cycloergometer at a level of 450 kpm/min. On separate days, subjects were exposed to 0 and 1.0 ppm SO2 in the absence of exercise. In exercising asthmatic subjects, breathing 1 ppm SO2 resulted in significant changes from baseline in airway resistance (Raw), forced expiratory volume in 1 sec (FEV1.0), maximal expiratory flow at 60% of the vital capacity (VC) below total lung capacity on the partial flow volume curve [MEF40% (P)] as well as reductions in flows at 50% of VC (Vmax50%). None of these parameters showed significant changes for exposures to 0.5 ppm or less, with the exception of small decreases (i.e., less than 0.2 L/sec) in Vmax50% at 0.25 and 0.5 ppm. Ten minutes after the end of exercise, there were no statistically significant differences from baseline, even though SO2 was still present in the chamber atmosphere. For asthmatic subjects, the average changes in Raw, FEV1.0, MEF40%(P), and Vmax50% increased as SO2 levels increased, suggestive of a dose-response relationship with a consistent effect first seen at 0.75 ppm. In individual exercising asthmatics, responses may occur at levels of SO2 below 0.75 ppm. No changes were seen in healthy individuals on any day, or in asthmatic subjects at rest.(ABSTRACT TRUNCATED AT 250 WORDS)
Airway Resistance↗
A study of respiratory effects from exposure to 2 ppm formaldehyde in healthy subjects.
Formaldehyde (FA) is a common indoor air pollutant with irritative properties. It has been suggested that FA may produce physiologic alterations of the respiratory system. To study such responses, 15 nonsmoking, healthy subjects were exposed in a double blind, random manner to 0 and 2 ppm FA for 40 min in an environmental chamber. In addition, the same exposures were repeated on a separate day with the subjects performing moderate exercise (450 kpm/min) for 10 min. Exposures were carried out under controlled environmental conditions (temperature = 23 degrees C, relative humidity = 50%). Pulmonary function was measured before, during, and after exposures using partial and maximal flow-volume curves and airway resistance. Symptom diaries were given to the subjects; upper and lower airway symptoms were recorded for up to 24 hr following exposures. No significant bronchoconstriction was noted in this group. In 3 subjects, sequential measurements of peak flow over a 24-hr period following FA exposure failed to reveal any delayed airway response. On a separate day, 6 healthy subjects failed to demonstrate changes from their baseline responsiveness to methacholine after exposure to 2 ppm FA. Respiratory symptoms were, in general, confined to the upper airways and were mild to moderate in severity. We conclude that short exposures to 2 ppm FA do not result in acute or subacute changes in lung function among healthy individuals either at rest or with exercise. Subjective complaints following such exposures are confined to irritative phenomena of the upper airways.
Adult↗