Indoor air pollutants in homes and schools

Exposure to the four indoor air pollutants mentioned in this article may cause illnesses and fatalities in children. It is important for pediatricians to be aware of each of them and to remove children from environments contaminated with these pollutants. Guidance about monitoring the indoor air and interpreting the results is difficult to find. A chart of proposed guidelines may help the pediatrician faced with an indoor air problem (Table 1).

Workshop to identify critical windows of exposure for children's health: immune and respiratory systems work group summary

Fetuses, infants, and juveniles (preadults) should not be considered simply "small adults" when it comes to toxicological risk. We present specific examples of developmental toxicants that are more toxic to children than to adults, focusing on effects on the immune and respiratory systems. We describe differences in both the pharmacokinetics of the developing immune and respiratory systems as well as changes in target organ sensitivities to toxicants. Differential windows of vulnerability during development are identified in the context of available animal models. We provide specific approaches to directly investigate differential windows of vulnerability. These approaches are based on fundamental developmental biology and the existence of discrete developmental processes within the immune and respiratory systems. The processes are likely to influence differential developmental susceptibility to toxicants, resulting in lifelong toxicological changes. We also provide a template for comparative research. Finally, we discuss the application of these data to risk assessment.

Workshop to identify critical windows of exposure for children's health: immune and respiratory systems work group summary

Fetuses, infants, and juveniles (preadults) should not be considered simply "small adults" when it comes to toxicological risk. We present specific examples of developmental toxicants that are more toxic to children than to adults, focusing on effects on the immune and respiratory systems. We describe differences in both the pharmacokinetics of the developing immune and respiratory systems as well as changes in target organ sensitivities to toxicants. Differential windows of vulnerability during development are identified in the context of available animal models. We provide specific approaches to directly investigate differential windows of vulnerability. These approaches are based on fundamental developmental biology and the existence of discrete developmental processes within the immune and respiratory systems. The processes are likely to influence differential developmental susceptibility to toxicants, resulting in lifelong toxicological changes. We also provide a template for comparative research. Finally, we discuss the application of these data to risk assessment.

Cardiopulmonary baroreceptor control of muscle sympathetic nerve activity in heat-stressed humans

Whole body heating decreases central venous pressure (CVP) while increasing muscle sympathetic nerve activity (MSNA). In normothermia, similar decreases in CVP elevate MSNA, presumably via cardiopulmonary baroreceptor unloading. The purpose of this project was to identify whether increases in MSNA during whole body heating could be attributed to cardiopulmonary baroreceptor unloading coincident with the thermal challenge. Seven subjects were exposed to whole body heating while sublingual temperature, skin blood flow, heart rate, arterial blood pressure, and MSNA were monitored. During the heat stress, 15 ml/kg warmed saline was infused intravenously over 7-10 min to increase CVP and load the cardiopulmonary baroreceptors. We reported previously that this amount of saline was sufficient to return CVP to pre-heat stress levels. Whole body heating increased MSNA from 25 +/- 3 to 39 +/- 3 bursts/min (P < 0. 05). Central blood volume expansion via rapid saline infusion did not significantly decrease MSNA (44 +/- 4 bursts/min, P > 0.05 relative to heat stress period) and did not alter mean arterial blood pressure (MAP) or pulse pressure. To identify whether arterial baroreceptor loading decreases MSNA during heat stress, in a separate protocol MAP was elevated via steady-state infusion of phenylephrine during whole body heating. Increasing MAP from 82 +/- 3 to 93 +/- 4 mmHg (P < 0.05) caused MSNA to decrease from 36 +/- 3 to 15 +/- 4 bursts/min (P < 0.05). These data suggest that cardiopulmonary baroreceptor unloading during passive heating is not the primary mechanism resulting in elevations in MSNA. Moreover, arterial baroreceptors remain capable of modulating MSNA during heat stress.

Air pollution and bronchitic symptoms in Southern California children with asthma

People who live in cities with dirty air have blacker lungs than people who live in rural areas with less air pollution. This is because, although particulates larger than 10 microm are filtered out when inhaled air passes through the nose, smaller particulates reach the lower airways. The particulates that reach the alveoli (the terminal air pockets of the lungs) stay there permanently. This accounts for the fact that a person who has lived in a polluted city for many years has blacker lungs than one who has lived in a polluted city for a shorter time.

Overview of investigations into pulmonary hemorrhage among infants in Cleveland, Ohio

Idiopathic pulmonary hemorrhage was diagnosed in 37 infants in the Cleveland, Ohio, area between 1993 and 1998. This rare disorder has been related to 12 deaths, including 7 originally thought to be sudden infant death syndrome. Thirty of the infants were African American, all of whom lived in a limited geographic area of eastern metropolitan Cleveland, an area of older housing stock. An investigation led by the Centers for Disease Control and Prevention has found an association with household exposure to a toxigenic mold, Stachybotrys chartarum, and other fungi. The rapidly growing lungs of young infants appear to be especially vulnerable to the toxins made by toxigenic molds. Environmental tobacco smoke was frequently present in the infants' homes and may be a trigger precipitating the acute bleeding. Stachybotrys, although not thought to be a common mold, is known to have a wide geographic distribution. An additional 101 cases of acute, idiopathic pulmonary hemorrhage have been reported in infants in the United States over the past 5 years. In this overview, the investigations are summarized, the clinical profile is described, the toxicity of S. chartarum is discussed, and pathophysiologic concepts are presented.

Effect of increasing central venous pressure during passive heating on skin blood flow

Whole body heating in humans increases skin blood flow (SkBF) and decreases central venous pressure (CVP). This study sought to identify whether elevations in SkBF are augmented during passive heating if CVP is increased during the heat stress. Seven subjects were exposed to passive heating. Once SkBF was substantially elevated, 15 ml/kg warm saline were rapidly infused intravenously. Whole body heating significantly increased cutaneous vascular conductance and decreased CVP from 7.7 +/- 0.6 to 4.9 +/- 0.5 mmHg (P < 0.05). Saline infusion returned CVP to pre-heat-stress pressures (7.9 +/- 0.6 mmHg; P > 0.05) and significantly increased cutaneous vascular conductance relative to the period before saline administration. Moreover, saline infusion did not alter mean arterial pressure, pulse pressure, or esophageal temperature (all P > 0.05). To serve as a volume control, 15 ml/kg saline were rapidly infused intravenously in normothermic subjects. Saline infusion increased CVP (P < 0.05) without affecting mean arterial pressure, pulse pressure, or cutaneous vascular conductance (all P > 0.05). These data suggest that cardiopulmonary baroreceptor unloading during passive heating may attenuate the elevation in SkBF in humans, whereas loading cardiopulmonary baroreceptors in normothermia has no effect on SkBF.

Study of toxin production by isolates of Stachybotrys chartarum and Memnoniella echinata isolated during a study of pulmonary hemosiderosis in infants

A cluster of cases of pulmonary hemosiderosis among infants was reported in Cleveland, Ohio, during 1993 and 1994. These unusual cases appeared only in infants ranging in age from 1 to 8 months and were characterized by pulmonary hemorrhage, which caused the babies to cough up blood. A case-control study identified major home water damage (from plumbing leaks, roof leaks, or flooding) as a risk factor for development of pulmonary hemorrhage in these infants. Because of an interest in the possibility that trichothecene mycotoxins might be involved in this illness, a number of isolates of Stachybotrys chartarum were grown in the laboratory on rice, and extracts were prepared and analyzed both for cytotoxicity and for specific toxins. Two isolates of Memnoniella echinata, a fungus closely related to S. chartarum, were also included in these studies. S. chartarum isolates collected from the homes were shown to produce a number of highly toxic compounds, and the profiles of toxic compounds from M. echinata were similar; the most notable difference was the fact that the principal metabolites produced by M. echinata were griseofulvins.

Acute pulmonary hemorrhage in infants associated with exposure to Stachybotrys atra and other fungi

BACKGROUND

A geographic cluster of 10 cases of pulmonary hemorrhage and hemosiderosis in infants occurred in Cleveland, Ohio, between January 1993 and December 1994.

STUDY DESIGN

This community-based case-control study tested the hypothesis that the 10 infants with pulmonary hemorrhage and hemosiderosis were more likely to live in homes where Stachybotrys atra was present than were 30 age- and ZIP code-matched control infants. We investigated the infants' home environments using bioaerosol sampling methods, with specific attention to S atra. Air and surface samples were collected from the room where the infant was reported to have spent the most time.

RESULTS

Mean colony counts for all fungi averaged 29 227 colony-forming units (CFU)/m3 in homes of patients and 707 CFU/m3 in homes of controls. The mean concentration of S atra in the air was 43 CFU/m3 in homes of patients and 4 CFU/m3 in homes of controls. Viable S atra was detected in filter cassette samples of the air in the homes of 5 of 9 patients and 4 of 27 controls. The matched odds ratio for a change of 10 units in the mean concentration of S atra in the air was 9.83 (95% confidence interval, 1.08-3 X 10(6)). The mean concentration of S atra on surfaces was 20 X 10(6) CFU/g and 0.007 x 10(6) CFU/g in homes of patients and controls, respectively.

CONCLUSION

Infants with pulmonary hemorrhage and hemosiderosis were more likely than controls to live in homes with toxigenic S atra and other fungi in the indoor air.

Children's health and the environment: a new agenda for prevention research

Patterns of illness in American children have changed dramatically in this century. The ancient infectious diseases have largely been controlled. The major diseases confronting children now are chronic and disabling conditions termed the "new pediatric morbidity"--asthma mortality has doubled; leukemia and brain cancer have increased in incidence; neurodevelopmental dysfunction is widespread; hypospadias incidence has doubled. Chemical toxicants in the environment as well as poverty, racism, and inequitable access to medical care are factors known and suspected to contribute to causation of these pediatric diseases. Children are at risk of exposure to over 15,000 high-production-volume synthetic chemicals, nearly all of them developed in the past 50 years. These chemicals are used widely in consumer products and are dispersed in the environment. More than half are untested for toxicity. Children appear uniquely vulnerable to chemical toxicants because of their disproportionately heavy exposures and their inherent biological susceptibility. To prevent disease of environmental origin in America's children, the Children's Environmental Health Network (CEHN) calls for a comprehensive, national, child-centered agenda. This agenda must recognize children's vulnerabilities to environmental toxicants. It must encompass a) a new prevention-oriented research focus; b) a new child-centered paradigm for health risk assessment and policy formulation; and c) a campaign to educate the public, health professionals, and policy makers that environmental disease is caused by preventable exposures and is therefore avoidable. To anchor the agenda, CEHN calls for long-term, stable investment and for creation of a national network of pediatric environmental health research and prevention centers.

Exposure to environmental tobacco smoke and risk factors for heart disease among never smokers in the Third National Health and Nutrition Examination Survey

The relative risk of coronary artery disease among never smokers exposed to environmental tobacco smoke (ETS) versus never smokers not exposed to ETS is approximately 1.2 based on more than a dozen epidemiologic studies. Most of these studies have controlled for the major heart disease risk factors, but residual or uncontrolled confounding remains a possible explanation for the epidemiologic findings. The authors studied 3,338 never-smoking adults aged 17 years or older, who are representative of all US never smokers, in the 1988-1991 Third National Health and Nutrition Examination Survey (NHANES III) to determine whether selected risk factors for heart disease differ between ETS-exposed and -nonexposed persons. Both self-reported ETS exposure (at home and at work) and serum cotinine levels were available, the latter reflecting recent ETS exposure. After adjustments were made for age, sex, race, and education among adults aged 17 years or older, no significant differences were found between the ETS exposed and the nonexposed for any of 13 cardiovascular risk factors with the exception of dietary carotene, which was lower among the exposed. On the other hand, significant positive linear trends were found between serum cotinine and two risk factors (body mass index and alcohol consumption), and significant inverse trends were found with dietary carotene. There were also few differences between exposed and nonexposed never smokers among adults aged 40 years or older, who are most at risk of heart disease. In this group, however, there was an inverse linear trend between serum cotinine and high density lipoprotein cholesterol (p < 0.001). This finding could result from ETS exposure rather than be an indication of confounding; a similar inverse trend was found for children, confirming other results in the literature. Overall, these data suggest little potential for confounding by the heart disease risk factors studied here when ETS exposure is determined by self-report.

Evidence of functional beta-adrenoceptors in the cutaneous vasculature

During a hyperthermic challenge, skin blood flow (SkBF) increases primarily through activation of the cutaneous active vasodilator system. However, mechanisms through which activation of this system elevates SkBF remain unknown. In this project, we sought to identify whether functional beta-adrenoceptors exist on cutaneous vessels and, if present, whether these receptors play an important role in elevating SkBF during a hyperthermic challenge. In protocol 1, SkBF was assessed over two intradermal microdialysis probes. Initially, both probes were perfused with lactated Ringer solution. Probe A was then perfused with a 200 microM solution of the beta-adrenoceptor agonist isoproterenol while probe B was perfused with a 1.7 mM solution of the beta-adrenoceptor antagonist propranolol. Isoproterenol perfusion significantly increased SkBF from 17.7 +/- 2.4 to 70.8 +/- 13.2 perfusion units (PU; P < 0.05), whereas propranolol perfusion did not significantly affect SkBF (23.4 +/- 6.5 to 27.0 +/- 6.8 PU; P > 0.05). After this period, the solutions perfusing the probes were switched. Isoproterenol did not significantly change SkBF at the propranolol-treated site (27.0 +/- 6.8 to 26.4 +/- 7.5 PU; P < 0.05). In protocol 2, SkBF was assessed over two microdialysis probes during indirect whole body heating. One probe was perfused with Ringer solution while the other probe was perfused with 1.7 mM propranolol. The degree of elevation in SkBF during heat stress at the propranolol-treated site (10.4 +/- 1.5 to 35.8 +/- 3.1 PU) was similar to the elevation in SkBF at the Ringer solution site (11.6 +/- 1.0 to 35.0 +/- 1.2 PU). These data demonstrate the presence of functional beta-adrenoceptors in the skin; however, these receptors play no significant role in mediating cutaneous vasodilation during indirect whole body heating.

Active and passive smoking: hazards for children

This manuscript describes the tobacco industry's efforts to recruit active smokers among the adolescent population, the effects of environmental tobacco smoke on nonsmokers, and lists some steps pediatricians can take to influence smoking behavior. Six health effects result from passive smoking. Children exposed to environmental tobacco smoke have increased lower respiratory illness rates, especially in the first year of life, passive smoking is associated with increased rates of chronic middle ear effusion in children. Exposure to cigarette smoke is associated with small changes in pulmonary function. Exposure to environmental tobacco smoke increases an asthmatic child's exacerbations. Exposure to environmental tobacco smoke is a risk factor for sudden infant death syndrome. Passive exposure during childhood to a parents smoking increases a child's risk of leukemia and lymphoma during adulthood. Pediatricians and others who care for children must try to limit as much as possible, the exposure of children to the cigarette smoke produced by others.

Reexamination of epidemic asthma in New Orleans, Louisiana, in relation to the presence of soy at the harbor

Epidemic asthma occurred in New Orleans, Louisiana, in the 1950s and 1960s, but its causes were never fully understood. Subsequently, similar outbreaks of epidemic asthma in Barcelona, Spain, were shown to be caused by the release of soy dust at the harbor. To investigate whether airborne soy dust may have contributed to epidemic asthma in New Orleans, the authors examined historical data on vessel cargo from the New Orleans harbor together with data on emergency department visits for asthma, for the period from 1957 through 1968. Days on which there were 64 or more visits for asthma were twice as likely to have occurred on days when a vessel carrying soy was at the harbor (odds ratio (OR) = 2.3, 95% confidence interval (CI) 1.5-3.3). The association was stronger when the maximum wind speed was less than 12 miles/hour (19.3 km/hour) (OR = 4.0, 95% CI 2.1-7.7) and strongest when wind speeds were low and the prevailing winds were from the south or southwest, the direction of two grain elevators from the hospital (OR = 6.7, 95% CI 1.5-46.7). Various temporal and climatic factors that had been associated with the occurrence of asthma outbreaks did not appear to be important confounding factors. The association was specific to soy cargo; no association was observed between asthma-epidemic days and the presence of either wheat or corn in vessels at the harbor. The results of this analysis provide further evidence that ambient soy dust is very asthmogenic and that asthma morbidity in a community can be influenced by exposures in the ambient atmosphere.

Environmental risk factors associated with pediatric idiopathic pulmonary hemorrhage and hemosiderosis in a Cleveland community

BACKGROUND

Unexplained pulmonary hemorrhage and hemosiderosis are rarely seen in infancy. A geographic cluster of 10 infants with this illness was identified in a large pediatric referral hospital in Cleveland, Ohio, during the period of January 1993 through December 1994. One infant died of severe respiratory failure.

METHODS

A case-control study was conducted. Three control infants were matched by age with each case infant. All study infants' guardians were interviewed. Questions were asked about child care practices and home conditions for the period before case infants' illnesses. All infants' records were reviewed, their homes were visited, and a structural and environmental survey was conducted.

RESULTS

All 10 case infants were black, and 9 were male, whereas 50.0% of control infants were male, and 83.3% were black. The case infants' mean age was 10.2 weeks (range, 6 weeks to 6 months). Matched analysis demonstrated that case infants' homes were more likely to have had water damage preceding the pulmonary hemorrhage event (odds ratio, 16.25; 95% confidence interval, 2.55 to infinity). Case infants were also more likely to have had close relatives with pulmonary hemorrhage (odds ratio, 33.14; 95% confidence interval, 5.10 to infinity). In addition, 50.0% of case infants experienced recurrent pulmonary hemorrhaging after returning to their homes.

CONCLUSION

The results of this investigation of a cluster of infants with massive, acute pulmonary hemorrhage and hemosiderosis suggest that the affected infants may have been exposed to contaminants in their homes. Epidemiologic clues, such as water damage in the case infants' homes, suggest that environmental risk factors may contribute to pulmonary hemorrhage.

Asthma. The states' challenge

At the national level, asthma is increasingly being recognized as an important public health problem. Because of the significant role of environmental exposure in asthma morbidity, public health agencies have a critical role to play in the surveillance and prevention of the disease. In April 1996, the Council of State and Territorial Epidemiologists, with assistance from the Centers for Disease Control and Prevention, surveyed state and territorial public health departments to determine the status of their asthma surveillance and intervention programs. Of the 51 health departments that responded, only eight reported that they had implemented an asthma control program within the previous 10 years. Reasons cited for not having programs included lack of funds, shortage of personnel, and asthma not being a priority. Most states were unable to assess the burden of asthma because they lack data or face barriers to using existing data. Removing barriers to the use of data is a first step toward defining the scope of the asthma problem.

Blood benzene concentrations in workers exposed to oxygenated fuel in Fairbanks, Alaska

OBJECTIVE

In November 1992 residents of Fairbanks, Alaska became concerned about the potential health effects of an oxygenated fuel program during which 15% (by volume) methyl tertiary butyl ether (MTBE) was added to gasoline. To address those concerns, we earlier completed a survey of occupational exposure to MTBE. We conducted a follow-up survey of workers' exposure to benzene from gasoline in Fairbanks.

DESIGN

Cross-sectional exposure survey.

METHODS

We examined blood concentrations of benzene from a convenience sample of workers taken in December 1992 during the oxygenated fuel program and from another convenience sample of workers taken in February 1993 after the program was suspended.

RESULTS

In December, the median blood benzene concentration of samples taken from four mechanics after their workshift (postshift) was 1.32 micrograms/l (range, 0.84-2.61 micrograms/l), and seven nonmechanics (drivers and other garage workers) had a median postshift blood benzene concentration of 0.27 microgram/l (range, 0.09-0.45 microgram/l). In February, nine mechanics had a median postshift blood benzene concentration of 1.99 micrograms/l (range, 0.92-3.23 micrograms/l), and nine nonmechanics had a median postshift blood benzene concentration of 0.26 microgram/l (range, 0.2-0.46 microgram/l).

CONCLUSION

Mechanics had higher blood benzene concentrations than did nonmechanics, but further study is needed to determine the impact of the oxygenated fuel program on exposure to benzene.

Mercury exposure in high school chemistry teachers

To assess whether high school chemistry teachers had higher urinary mercury concentrations than other high school teachers, 24 high school teachers from nine schools in northeastern Ohio were studied. First morning voided urine samples and air samples from the teachers' classrooms were analyzed for total mercury content by cold vapor atomic absorption. The median adjusted urinary mercury concentration in the 12 chemistry teachers was 4.6 microg/g creatinine (range 2.2-8.2 microg/g creatinine) and it was 6.3 microg/g creatinine in the 12 non-chemistry teachers. All classroom air samples contained mercury levels below detection limits. No evidence was provided that high school chemistry teachers are at increased risk of chronic mercury exposure from their teaching activities compared to other high school teachers.

Effects of air pollution on the respiratory health of asthmatic children living in Mexico City

The relation between air pollution and the exacerbation of childhood asthma was studied in a panel of 71 children (aged 5 to 7 yr) with mild asthma who resided in the northern part of mexico City. During the follow-up, ambient measures of particulate matter less than 10 microns (PM10, 24-h average) and ozone (1-h maximum) frequently exceeded the Mexican standards for these contaminants. The peak expiratory flow rate (PEFR) was strongly associated with PM10 levels and marginally with ozone levels. Respiratory symptoms (coughing, phlegm production, wheezing, and difficulty breathing) were associated with both PM10 and ozone levels. An increase of 20 micrograms/m3 of PM10 was related to an 8% increase in lower respiratory illness (LRI) among children on the same day (95% confidence interval [CI] = 1.04-1.15), and an increase of 10 micrograms/m3 in the weekly mean of particulate matter less than 2.5 microns (PM2.5) was related to a 21% increase in LRI (95% CI = 1.08-1.35). A 50 parts per billion (ppb) increase in ozone was associated with a 9% increase in LRI (95% CI = 1.03-1.15) on the same day. We concluded that children with mild asthma are affected by the high ambient levels of particulate matter and ozone observed in the northern part of Mexico City.

Toxigenic molds in water-damaged buildings: dechlorogriseofulvins from Memnoniella echinata

An investigation of a cluster of cases of pulmonary hemosiderosis in infants in Cleveland, OH, led to the isolation of many isolates of Stachybotrys atra and two isolates of a related toxigenic fungus, Memnoniella echinata. M. echinata produces two cytotoxic trichothecene mycotoxins, trichodermol (1a) and trichodermin (1b), as well as several griseofulvins. Dechlorogriseofulvin (2a) and epidechlorogriseofulvin (2b) were the major compounds isolated. This is the first report of a fungus outside the Penicillium genus producing griseofulvins.

Pulmonary fibrosis deaths in the United States, 1979-1991. An analysis of multiple-cause mortality data

We sought to describe pulmonary fibrosis mortality in the United States from 1979 through 1991 by analyzing death certificate reports compiled by the National Center for Health Statistics. Of the 26,866,600 people who died during the study period, 107,292 had a diagnosis of pulmonary fibrosis listed on their death certificates. Among men, age-adjusted mortality rates increased from 48.6 per 1,000,000 in 1979 to 50.9 per 1,000,000 in 1991 and, among women, these rates increased from 21.4 per 1,000,000 in 1979 to 27.2 per 1,000,000 in 1991. Among both men and women rates were higher in older age strata than in younger age strata. Age-adjusted mortality rates were consistently higher among whites and people of races than blacks. The frequency with which pulmonary fibrosis was listed as the underlying cause of death increased from 40% in 1979 to 56% in 1991. Age-adjusted mortality rates varied by state, with lowest rates in the Midwest and Northeast, and the highest rates in the West and Southeast. We conclude that the age-adjusted rate of pulmonary fibrosis among decedents in the United States increased, and pulmonary fibrosis was listed as the underlying cause of death with increasing frequency, over the study period. We cannot determine whether the differences we detected between regions, sexes, and races are related to characteristics of the disease or problems in death certification and coding.

Exposure of the US population to environmental tobacco smoke: the Third National Health and Nutrition Examination Survey, 1988 to 1991

OBJECTIVE

To estimate the extent of exposure of the US population to environmental tobacco smoke and the contribution of the home and workplace environment to environmental tobacco smoke exposure.

DESIGN

Nationally representative cross-sectional survey including questionnaire information from persons aged 2 months and older (n=16818) and measurements of serum cotinine (a metabolite of nicotine) from persons aged 4 years and older (n=10642).

SETTING/PARTICIPANTS

Participants in the Third National Health and Nutrition Examination Survey, October 25, 1988, to October 21, 1991.

RESULTS

Of US children aged 2 months to 11 years, 43% lived in a home with at least 1 smoker, and 37% of adult non-tobacco users lived in a home with at least 1 smoker or reported environmental tobacco smoke exposure at work. Serum cotinine levels indicated more widespread exposure to nictoine. Of non-tobacco users, 87.9% had detectable levels of serum cotinine. Both the number of smokers in the household and the hours exposed at work were significantly and independently associated (P<.001, multiple regression t test) with increased serum cotinine levels. Serum cotinine levels of children, non-Hispanic blacks, and males indicated that these groups had higher exposure to environmental tobacco smoke. Dietary variables showed no consistent association with serum cotinine levels, and dietary contribution to serum cotinine level, if any, appeared to be extremely small.

CONCLUSIONS

The high proportion of the population with detectable serum cotinine levels indicates widespread exposure to environmental tobacco smoke in the US population. Both the home and workplace environments significantly contribute to environmental tobacco smoke exposure in the United States.

Use of a 24-hour recall diary to assess exposure to environmental tobacco smoke

Methods to assess exposure to environmental tobacco smoke need to be valid and relatively easy to use. We therefore explored the use of a 24-h environmental tobacco smoke exposure-recall diary by comparing data from the 24-h diary with questionnaire responses and levels of salivary cotinine--a biochemical marker of environmental tobacco smoke exposure. A total of 875 nonsmokers at five Rhode Island worksites participated in the study. Twenty-five percent of the participants lived with smokers, and 96% had regular exposure to environmental tobacco smoke at work. Individuals who lived with smokers reported more exposures in the 24-h diary, both outside of work and during work hours, compared with those who had no smokers in their household. The correlation between saliva cotinine concentrations and the exposures recorded in the diary was weak (r = .10). Brief instruments for assessment of environmental tobacco smoke should be viewed cautiously, and use of this 24-h recall diary is not recommended.

Unintentional deaths from carbon monoxide poisoning in New Mexico, 1980 to 1988. A comparison of medical examiner and national mortality data

Carbon monoxide was the number 1 cause of poisoning deaths in the United States from 1980 through 1988, with the highest rates reported in the western states. We studied unintentional deaths from carbon monoxide poisoning in New Mexico during this period using the multiple-cause mortality files from the National Center for Health Statistics (NCHS) and data from the New Mexico Office of the Medical Investigator (OMI). We compared the nationally available NCHS data with the more detailed OMI data to determine the sensitivity of NCHS data for the surveillance of this preventable cause of death. The NCHS data were 88% sensitive in identifying deaths from unintentional carbon monoxide poisoning and had a positive predictive value of 81% when compared with OMI data. Half of the unintentional carbon monoxide-related deaths were attributable to a home heating mechanism of some sort, 46% involved motor vehicle exhaust, and at least 42% were associated with alcohol use. We conclude that available NCHS data are a sensitive source of surveillance information about unintentional deaths from carbon monoxide poisoning. Additional details about specific deaths can be obtained from medical examiner files when needed.

Indoor air pollution and childhood asthma: effective environmental interventions

Exposure to indoor air pollutants such as tobacco smoke and dust mites may exacerbate childhood asthma. Environmental interventions to reduce exposures to these pollutants can help prevent exacerbations of the disease. Among the most important interventions is the elimination of environmental tobacco smoke from the environments of children with asthma. However, the effectiveness of reducing asthmatic children's exposure to environmental tobacco smoke on the severity of their symptoms has not yet been systematically evaluated. Dust mite reduction is another helpful environmental intervention. This can be achieved by enclosing the child's mattresses, blankets, and pillows in zippered polyurethane-coated casings. Primary prevention of asthma is not as well understood. It is anticipated that efforts to reduce smoking during pregnancy could reduce the incidence of asthma in children. European studies have suggested that reducing exposure to food and house dust mite antigens during lactation and for the first 12 months of life diminishes the development of allergic disorders in infants with high total IgE in the cord blood and a family history of atopy. Many children with asthma and their families are not receiving adequate counseling about environmental interventions from health care providers or other sources.

Effects of urban air pollutants on emergency visits for childhood asthma in Mexico City

The metropolitan area of Mexico City, Mexico, has serious air pollution problems. Although air contaminants may contribute to clinical asthma, there are at present no data on the relation between air pollution exposure and childhood asthma in Mexico City. The authors reviewed data on emergency visits from January to June 1990 at one major pediatric hospital in Mexico City. They used a Poisson regression model to study the relation between the number of daily emergency visits for asthma and air pollutant levels. The levels of ozone and sulfur dioxide-exposure were significantly associated with the number of emergency visits for asthma. After adjustment for potential confounding factors, the multivariate regression model predicted that an increase of 50 ppb in the 1-hour maximum ozone level would lead to a 43% increase in the number of emergency visits for asthma on the following day. Exposure to high ozone levels (> 110 ppb) for 2 consecutive days increased the number of asthma-related emergency visits by 68 percent. The results of this study suggest that ozone exposure is positively associated with the number of children's emergency visits for asthma in Mexico City.

Out-of-hospital deaths due to asthma in North Carolina, 1980-1988

Because deaths that occur outside hospitals have not been well-described, we studied out-of-hospital deaths from asthma in North Carolina from 1980 through 1988. We investigated out-of-hospital deaths from asthma using information from the North Carolina Office of the Chief Medical Examiner. We excluded deaths for which a hospital was listed as the place where the death occurred. For the nine years studied, the Office of the Chief Medical Examiner recorded 89 of 158 investigated deaths from asthma as having occurred out of hospital. Of the 89 deaths, 73% occurred in the decedent's home. The rates of out-of-hospital deaths from asthma increased as the age of the decedents increased, were higher in rural countries than they were in urban counties, and were over three times higher for blacks and American Indians than they were for whites. Racial minorities may warrant special attention in any attempt to prevent out-of-hospital deaths due to asthma.

Methyl tertiary butyl ether in human blood after exposure to oxygenated fuel in Fairbanks, Alaska

Residents of Fairbanks, Alaska reported health complaints when 15%, by volume, methyl tertiary butyl ether (MTBE) was added to gasoline during an oxygenated fuel program. We conducted an exposure survey to investigate the effect of the program on human exposure to MTBE. We studied 18 workers in December 1992 during the program and 28 workers in February 1993 after the program was suspended. All workers were heavily exposed to motor vehicle exhaust or gasoline fumes. In December, the median post-shift blood concentration of MTBE in the workers was 1.8 micrograms/l (range, 0.2-37.0 micrograms/l), and in February the median post-shift blood concentration of MTBE in the 28 workers was 0.24 micrograms/l (range, 0.05-1.44 micrograms/l; p = .0001). Blood MTBE levels were measurably higher during the oxygenated fuel program in Fairbanks than after the program was suspended.

Volatile organic compounds in the blood of persons in Kuwait during the oil fires

Between March and November of 1991, approximately 9000 workers from 43 different countries battled the burning oil wells in Kuwait. To document the exposure of persons in Kuwait during the oil well fires to volatile organic compounds (VOCs), we obtained samples of blood from 14 U.S. personnel in Kuwait City in May of 1991 (group I) and 40 American firefighters working in the oil fields in October of 1991 (group II). Concentrations of VOCs in group I and group II were compared with those of a random sample of 114 persons in the United States (reference group). The median concentrations of VOCs in group I were equal to or lower than those in the reference group. We found significant differences between the median concentrations of several VOCs in group II and the reference group. Median levels of ethylbenzene were about 10 times higher among group II than among the reference group (0.53 microgram/l vs 0.052 microgram/l). Median levels of benzene, m-/p-xylene, o-xylene, styrene, and toluene among group II were more than double those of the reference group. Although firefighters had higher median concentrations of VOCs than the reference group, those American personnel in Kuwait not involved in fighting the oil fires had concentrations of VOCs comparable to those in the reference group. Blood VOC measurements indicate a significant increase in exposure to VOCs in firefighters, but do not demonstrate this in personnel in Kuwait City.

Surveillance for dust storms and respiratory diseases in Washington State, 1991

Southeast Washington State, which has a long history of seasonal dust storms, experienced 2 d of dust storms in October 1991, during which PM10 levels exceeded 1,000 micrograms/m3 (i.e., six times greater than the Environmental Protection Agency's 24-h PM10 standard). Three community hospitals in southeast Washington were visited for the purpose of assessing the possible effects of dust storms on respiratory health. During these visits, the number of emergency room visits for respiratory disorders for each day of 1991 were abstracted. These numbers were compared with daily PM10 levels for 1991. Also determined were the observed/expected ratios for the number of emergency room visits for each respiratory disorder category during October 1991. The maximum observed/expected ratio for the respiratory disorders was 1.2. For 1991, we found a 3.5% increase in the number of daily emergency room visits for bronchitis for each 100 micrograms/m3 increase in PM10. In addition, 2 d subsequent to those days on which the PM10 levels exceeded 150 micrograms/m3, there was a 4.5% increase in the number of emergency room visits for sinusitis for each 100 micrograms/m3 increase in PM10. Our results indicate that the naturally occurring PM10 in this setting has a small effect on the respiratory health of the population in general.

Exacerbations of childhood asthma and ozone pollution in Atlanta

Asthma prevalence and mortality due to asthma have been increasing during the last decade, and both the rates and the increases in rates have been higher for blacks than whites and higher for children than adults. Whether environmental factors such as air pollution contribute to these increases is unknown. The purpose of this study was to examine the relationship between emergency visits to a hospital for childhood asthma and exposure to ozone in an indigent, predominantly black population. Data were collected by abstracting clinical records for all children with asthma or reactive airway disease in one public hospital during the summer of 1990. From June 1, 1990, to August 31, 1990, 609 visits were made by children aged 1 to 16 years to an emergency clinic for treatment of asthma or reactive airway disease. Monitoring data indicated that maximum ozone levels equalled or exceeded 0.11 ppm on 6 days during the study period. The average number of visits for asthma or reactive airway disease was 37% higher on the days after those 6 days (from 6:00 PM to 6:00 PM the next day) than on other days (95% CI, RR = 1.02-1.73). The results of the study suggest that among black children from low-income families, asthma may be exacerbated following periods of high ozone pollution.

An evaluation of the relationship between self-report and biochemical measures of environmental tobacco smoke exposure

To evaluate the relationship between self-reported exposure to environmental tobacco smoke and saliva cotinine concentrations, we studied 186 nonsmokers. Each participant completed an exposure questionnaire, kept a daily exposure diary for 7 days, and provided a saliva sample for cotinine analysis. Salivary cotinine concentrations were measured using gas chromatography/mass spectrometry. Of the volunteers, 30% lived with one or more smokers, and 84% were regularly exposed to smokers at work. Eighty-three percent of the volunteers had detectable saliva cotinine concentrations (> or = 0.5 ng/ml) (median = 1.1; range = 0.5-7.4 ng/ml). Cotinine concentrations were related to exposure in the household and at the workplace. Volunteers who lived with smokers had significantly higher cotinine levels (median = 1.0; range = < 0.5-7.4 ng/ml) than those who did not (median = < 0.5; range = < 0.5-4.7 ng/ml). Volunteers who reported regular exposure at work had higher cotinine levels (median = 0.8; range = < 0.5-7.4 ng/ml) than those who did not (median = < 0.5; range = < 0.5-3.0 ng/ml). Cotinine concentrations were predicted by a regression equation that included the number of smokers at home and work and the number of minutes of exposure recorded in the daily diary (r2 = 0.29).

Do the medical history and physical examination predict low lung function?

BACKGROUND

We sought to determine whether an abnormal respiratory history or chest physical examination could be used to identify men with low lung function.

METHODS

We analyzed pulmonary function, physical examination, and questionnaire data from 4461 middle-aged male Vietnam-era army veterans.

MAIN RESULTS

The study sample consisted of 1161 never smokers, 1292 former smokers, and 2008 current smokers. Clinical indicators of respiratory disease (respiratory symptoms, respiratory signs, or a history of respiratory disease), were present in 26.1% of the never smokers, 31.7% of the former smokers, and 47.2% of the current smokers. We defined low forced expiratory volume in 1 second as a value less than 81.2% of the predicted value. Seven percent of the never smokers, 8% of the former smokers, and 17.3% of the current smokers demonstrated low forced expiratory volume in 1 second. Among those with a clinical indicator for spirometry only 11% of the never smokers, 13% of the former smokers, and 21% of the current smokers actually had a low forced expiratory volume in 1 second. Among those without a clinical indicator 6% of the never smokers, 6% of the former smokers, and 14% of the current smokers actually had a low forced expiratory volume in 1 second.

CONCLUSIONS

The use of clinical indicators as a basis for obtaining pulmonary function tests in middle-aged men misses many with low lung function, especially current smokers.

Black spots on the scalps of schoolchildren. A recurrent condition in the windy west

During the past 10 years, epidemics of black spots on the scalps of schoolchildren have caused considerable concern in at least 4 communities in the Rocky Mountain states. We describe the clinical presentation of "black spots" in a group of Wyoming elementary school students and the epidemiologic investigation that revealed the cause. Our study included a questionnaire survey of students' parents, examination of students at the affected school and at two other schools, observation of playground activity patterns, and laboratory analysis of specimens taken from affected children and from the school environment. The black material in the scalp spots was chemically identical to flakes of black material found on the playground and tar from the school roof. We concluded that the spots were caused by flakes of windblown tar from the school roof. Previous outbreaks of black spots may have had a similar cause.

Respiratory disease surveillance in Hungary

In October 1989, the Hungarian National Institute of Hygiene initiated the Children's Acute Respiratory Morbidity (CHARM) Surveillance System to assess the association between nine reportable respiratory diseases and air pollution. The weekly number of physician-diagnosed, reportable respiratory diseases among four age groups of children (less than 1, 1-2, 3-5, and 6-14 years) was tabulated for Sopron, a city with 60,000 residents. We calculated the proportion of diseases occurring during weeks with low, moderate, and high sulfur dioxide (SO2) and nitrogen dioxide (NO2) concentrations. The weekly averages of the 24-hour median SO2 concentrations were divided into thirds at less than or equal to 17.6, greater than 17.6 to less than or equal to 26.3, and greater than 26.3 micrograms/m3 (range: 0.9-79.6 micrograms/m3), and the NO2 concentrations at less than or equal to 29.8, greater than 29.8 to less than or equal to 44.1, and greater than 44.1 micrograms/m3 (range: 4.2-90.1 micrograms/m3). During 1990, 11,474 respiratory disease cases occurred among the 4,020 children less than 15 years of age living in Sopron and monitored by the CHARM system. The two most frequently reported disease categories were rhinitis/tonsillitis/pharyngitis (71.5%) and acute bronchitis (8.5%). Sixty-seven percent of pneumonia cases occurred when SO2 concentrations were highest. We found no association between levels of NO2 and respiratory diseases. The CHARM Surveillance System may characterize more fully which groups of children develop particular respiratory diseases following exposure to air pollution.

Passive smoking and middle ear effusion among children in day care

One hundred thirty-two children who attended a research day-care center were studied to determine whether passive tobacco smoke exposure was associated with an increased rate of otitis media with effusion or with an increased number of days with otitis media with effusion during the first 3 years of life. Based on preliminary studies, a serum cotinine concentration of greater than or equal to 2.5 ng/mL was considered indicative of exposure to tobacco smoke. Otitis media with effusion was diagnosed using pneumatic otoscopy by nurse practitioners and pediatricians who reviewed the children's health status each weekday. The 87 children with serum cotinine concentrations greater than or equal to 2.5 ng/mL had a 38% higher rate of new episodes of otitis media with effusion during the first 3 years of life than the 45 children with lower or undetectable serum cotinine concentrations (incidence density ratio = 1.38, 95% confidence interval 1.21 to 1.56). The average duration of an episode of otitis media with effusion was 28 days in the children with elevated cotinine concentrations and 19 days in the children with lower cotinine concentrations (P less than .01). It is estimated that 8% of the cases of otitis media with effusion in this population and 17.6% of the days with otitis media with effusion may be attributable to exposure to tobacco smoke.

Exposure to environmental tobacco smoke in naturalistic settings

BACKGROUND

Exposure to environmental tobacco smoke (ETS) has been identified as a risk factor for chronic disease among nonsmokers. Results of epidemiological surveys suggest that the majority of nonsmokers have regular ETS exposure. However, little is known about the topography of exposure.

METHODS

An exposure diary was used by 186 nonsmokers to self-monitor ETS exposure over a 7-day period. Subjects also completed a questionnaire that assessed their patterns of ETS exposure.

RESULTS

The primary source of ETS exposure was the workplace, except when there was a smoker in the household, in which case the household was the primary source. The presence of a smoker in the household resulted in higher levels of exposure both at work and in other locations when compared with subjects without household exposure. Subjects' assessments of exposure on the questionnaire were consistently lower than their self-monitored levels. This finding suggests that general exposure ratings underestimate exposure.

CONCLUSIONS

This study provides a new understanding of the patterns of ETS exposure and may help guide the development of policies and interventions designed to reduce ETS exposure.

Passive smoking alters lipid profiles in adolescents

Although cigarette smoking is associated with elevation of plasma lipid levels and changes in lipoprotein distribution, it is not known whether passive smoking is associated with an alteration in lipid profiles. The relation between plasma cotinine, a marker of exposure to tobacco smoke, and lipid profiles was studied in healthy adolescents from a suburban New York high school district who were undergoing preparticipation sports physicals. Forty-four percent of the adolescents reported that one or both parents currently smoked. Eleven percent of the adolescents had plasma cotinine concentrations greater than or equal to 2.5 ng/mL, the level considered indicative of exposure. Adolescents with two smoking parents had significantly higher plasma cotinine concentrations after adjustment for other factors than adolescents whose parents did not smoke. Plasma cotinine concentration greater than or equal to 2.5 ng/mL was associated with an 8.9% greater ratio of total cholesterol to high-density lipoprotein cholesterol (P less than .003) and a 6.8% lower high-density lipoprotein cholesterol (P less than .03). These results suggest that passive smoking, like active smoking, leads to alterations in lipid profiles predictive of an increased risk of atherosclerosis.

Mercury exposure from interior latex paint

BACKGROUND

Many paint companies have used phenylmercuric acetate as a preservative to prolong the shelf life of interior latex paint. In August 1989, acrodynia, a form of mercury poisoning, occurred in a child exposed to paint fumes in a home recently painted with a brand containing 4.7 mmol of mercury per liter (at that time the Environmental Protection Agency's recommended limit was 1.5 mmol or less per liter).

METHODS

To determine whether the recent use of that brand of paint containing phenylmercuric acetate was associated with elevated indoor-air and urinary mercury concentrations, we studied 74 "exposed" persons living in 19 homes recently painted with the brand and 28 "unexposed" persons living in 10 homes not recently painted with paint containing mercury.

RESULTS

The paint samples from the homes of exposed persons contained a median of 3.8 mmol of mercury per liter, and air samples from the homes had a median mercury content of 10.0 nmol per cubic meter (range, less than 0.5 to 49.9). No mercury was detected in paint or air samples from the homes of unexposed persons. The median urinary mercury concentration was higher in the exposed persons (4.7 nmol of mercury per millimole of creatinine; range, 1.4 to 66.5) than in the unexposed persons (1.1 nmol per millimole; range, 0.02 to 3.9; P less than 0.001). Urinary mercury concentrations within the range that we found in exposed persons have been associated with symptomatic mercury poisoning.

CONCLUSIONS

We found that potentially hazardous exposure to mercury had occurred among persons whose homes were painted with a brand of paint containing mercury at concentrations approximately 2 1/2 times the Environmental Protection Agency's recommended limit.

Laboratory investigation of a poisoning epidemic in Sierra Leone

In June 1986, an epidemic of poisoning occurred in Sierra Leone, West Africa; it involved 49 persons--with 14 deaths. Our laboratory's approach and investigation of this incident is described. Using positive chemical ionization mass spectrometry and nuclear magnetic resonance spectroscopy, the toxicant was identified as parathion, a highly toxic organophosphorus pesticide. Analysis of various items supported the epidemiologic hypothesis that bread was made from contaminated flour and that the flour became contaminated with parathion during a truck shipment. Modern analytical instruments played a major role in this laboratory investigation and effected the identification of the unknown toxicant within hours of receiving the initial bread sample. Close cooperation and clear communication between the epidemiologic and laboratory teams were important in this investigation.

A review of the use of saliva cotinine as a marker of tobacco smoke exposure

Cotinine, the major metabolite of nicotine, is a useful marker of exposure to tobacco smoke. It can be measured in plasma, urine, or saliva. However, distinguishing between active and passive smoking on the basis of a cotinine measurement may be difficult. In order to evaluate the relationship between saliva cotinine concentration and self-reported tobacco smoke exposure in both active and passive smokers, an English-language literature search using MEDLINE was conducted (1973-1989), and the bibliographies of identified articles were reviewed. Of 43 originally identified articles, only 22 met the criteria for inclusion. Specific information regarding population studied, reported tobacco smoke exposure, method of measurement, and cotinine concentrations was assessed. Passive smokers usually have cotinine concentrations in saliva below 5 ng/ml, but heavy passive exposure can result in levels greater than or equal to 10 ng/ml. Levels between 10 and 100 ng/ml may result from infrequent active smoking or regular active smoking with low nicotine intake. Levels greater than 100 ng/ml are probably the result of regular active smoking. Four categorizations of tobacco smoke exposure are suggested on the basis of saliva cotinine concentrations.

Lethal paralytic shellfish poisoning in Guatemala

An outbreak of paralytic shellfish poisoning occurred in Champerico, on the Pacific coast of Guatemala, July-August 1987. Of 187 people affected with characteristic neurologic symptoms, 26 died. A case study implicated a species of clam, Amphichaena kindermani, harvested from local beaches as the vehicle of the neurotoxins (saxitoxins). Children less than 6 years old had a higher fatality rate (50%) than people greater than 18 years of age (7%). The minimum lethal dose for 1 child was estimated to have been 140 mouse units of toxin/kg body weight; thus children may be more sensitive to the saxitoxins than are adults. This is the first large outbreak of paralytic shellfish poisoning recognized in Guatemala.

Surveillance for adverse health effects following a chemical release in west virginia

On 11 August 1985, a large inadvertent release occurred from a chemical manufacturing plant in Institute, West Virginia. The emission was related to overheating of a storage tank that contained chemicals for the production of aldicarb, a cholinesterase inhibiting pesticide. As a result of this emission, 136 persons were treated in five local emergency rooms, 29 of whom were hospitalized for one or more days, mostly for observation. No fatalities resulted. Interviews with treated persons and non-treated community residents confirmed that the health effects were transient and compatible with exposure to irritating vapors rather than with exposure to methyl isocyanate (a chemical used in the process) or to aldicarb. Only 5% of the treated persons and 5% of the community residents surveyed were adequately warned of the emission by the plant siren. Because persons in the nearby community are potentially vulnerable to chemical injury, we recommend the development of an improved warning system, a formal evacuation procedure, and other measures to limit exposure of persons in this area in the event of a future release.