ABSTRACT
OBJECTIVES: To assess the influence of clinical status on the association between total plasma bilirubin and unbound bilirubin on death or adverse neurodevelopmental outcomes at 18-22 months corrected age in extremely low birth weight infants. METHOD: Total plasma bilirubin and unbound bilirubin were measured in 1101 extremely low birth weight infants at 5 +/- 1 days of age. Clinical criteria were used to classify infants as clinically stable or unstable. Survivors were examined at 18-22 months corrected age by certified examiners. Outcome variables were death or neurodevelopmental impairment, death or cerebral palsy, death or hearing loss, and death prior to follow-up. For all outcomes, the interaction between bilirubin variables and clinical status was assessed in logistic regression analyses adjusted for multiple risk factors. RESULTS: Regardless of clinical status, an increasing level of unbound bilirubin was associated with higher rates of death or neurodevelopmental impairment, death or cerebral palsy, death or hearing loss and death before follow-up. Total plasma bilirubin values were directly associated with death or neurodevelopmental impairment, death or cerebral palsy, death or hearing loss, and death before follow-up in unstable infants, but not in stable infants. An inverse association between total plasma bilirubin and death or cerebral palsy was found in stable infants. CONCLUSIONS: In extremely low birth weight infants, clinical status at 5 days of age affects the association between total plasma bilirubin and death or adverse neurodevelopmental outcomes at 18-22 months of corrected age. An increasing level of UB is associated a higher risk of death or adverse neurodevelopmental outcomes regardless of clinical status. Increasing levels of total plasma bilirubin are directly associated with increasing risk of death or adverse neurodevelopmental outcomes in unstable, but not in stable infants.
Subject(s)
Bilirubin/blood , Developmental Disabilities/epidemiology , Health Status , Hyperbilirubinemia, Neonatal/complications , Infant Mortality , Infant, Extremely Low Birth Weight/growth & development , Cerebral Palsy/etiology , Developmental Disabilities/etiology , Follow-Up Studies , Hearing Loss/etiology , Humans , Hyperbilirubinemia, Neonatal/mortality , Infant, Extremely Low Birth Weight/blood , Infant, Newborn , Logistic Models , Risk FactorsABSTRACT
OBJECTIVES: To identify the variables that predict death/physiologic bronchopulmonary dysplasia (BPD) in preterm infants with severe respiratory failure. STUDY DESIGN: The study was a secondary analysis of data from the NICHD Neonatal Research Network trial of inhaled nitric oxide (iNO) in preterm infants. Stepwise logistic regression models and Classification and Regression Tree (CART) models were developed for the outcome of death or physiologic BPD (O(2) at 36 weeks post-menstrual age). RESULT: Death and/or BPD was associated with lower birth weight, higher oxygen requirement, male gender, additional surfactant doses, higher oxygenation index and outborn status, but not the magnitude of response in PaO(2) to iNO. The positive predictive value of the CART model was 82% at 95% sensitivity. CONCLUSIONS: The major factors associated with death/BPD were an increased severity of respiratory failure, lower birth weight, male gender and outborn status, but not the magnitude of initial response to iNO.
Subject(s)
Bronchopulmonary Dysplasia/epidemiology , Respiratory Insufficiency/epidemiology , Algorithms , Humans , Infant, Newborn , Infant, Premature , Logistic Models , Models, Statistical , Respiratory Insufficiency/mortalityABSTRACT
OBJECTIVES: We hypothesized that inhaled nitric oxide (iNO) would not decrease death or neurodevelopmental impairment (NDI) in infants enrolled in the National Institute of Child Health and Human Development Preemie iNO Trial (PiNO) trial, nor improve neurodevelopmental outcomes in the follow-up group. STUDY DESIGN: Infants <34 weeks of age, weighing <1500 g, with severe respiratory failure were enrolled in the multicenter, randomized, controlled trial. NDI at 18 to 22 months corrected age was defined as: moderate to severe cerebral palsy (CP; Mental Developmental Index or Psychomotor score Developmental Index <70), blindness, or deafness. RESULTS: Of 420 patients enrolled, 109 who received iNO (52%) and 98 who received placebo (47%) died. The follow-up rate in survivors was 90%. iNO did not reduce death or NDI (78% versus 73%; relative risk [RR], 1.07; 95% CI, 0.95-1.19), or NDI or Mental Developmental Index <70 in the follow-up group. Moderate-severe CP was slightly higher with iNO (RR, 2.41; 95% CI, 1.01-5.75), as was death or CP in infants weighing <1000 g (RR, 1.22; 95% CI, 1.05-1.43). CONCLUSIONS: In this extremely ill cohort, iNO did not reduce death or NDI or improve neurodevelopmental outcomes. Routine iNO use in premature infants should be limited to research settings until further data are available.
Subject(s)
Infant, Premature , Nervous System/growth & development , Nitric Oxide/administration & dosage , Respiratory Distress Syndrome, Newborn/drug therapy , Respiratory Distress Syndrome, Newborn/mortality , Administration, Inhalation , Chi-Square Distribution , Child Development/drug effects , Developmental Disabilities/prevention & control , Dose-Response Relationship, Drug , Double-Blind Method , Drug Administration Schedule , Female , Follow-Up Studies , Humans , Infant, Newborn , Male , Nervous System/drug effects , Poisson Distribution , Respiratory Distress Syndrome, Newborn/diagnosis , Risk Assessment , Severity of Illness Index , Statistics, Nonparametric , Survival Rate , Treatment OutcomeABSTRACT
OBJECTIVE: To examine the association between weight loss during the first 10 days of life and the incidence of death or bronchopulmonary dysplasia (BPD) in small for gestational age (SGA) and appropriate for gestational age (AGA) extremely low-birth-weight infants. DESIGN/METHODS: This is a retrospective analysis of a cohort of ELBW (birth weight <1000 g) infants from the NICHD Neonatal Research Network's database. The cohort consisted of 9461 ELBW infants with gestational age of 24-29 weeks, admitted to Network's participating centers during calendar years 1994-2002 and surviving at least 72 h after birth. The cohort was divided into two groups, 1248 SGA (with birth weight below 10th percentile for gestational age) and 8213 AGA (with birth weight between 10th and 90th percentile) infants. We identified infants with or without weight loss during the first 10 days of life, which we termed as 'early postnatal weight loss' (EPWL). Univariate analyses were used to predict whether EPWL was related to the primary outcome, death or BPD, within each birth weight/gestation category (SGA or AGA). BPD and death were also analyzed separately in relation to EPWL. Logistic regression analysis was done to evaluate the risk of death or BPD in SGA and AGA groups, controlling for maternal and neonatal demographic and clinical factors found to be significant by univariate analysis. RESULTS: SGA ELBW infants had a lower prevalence of EPWL as compared with AGA ELBW infants (81.2 vs 93.7%, respectively, P<0.001). In AGA infants, univariate analysis showed that death or BPD rate was lower in the group of infants with EPWL compared with infants without EPWL (53.4 vs 74.3%, respectively, P<0.001). The BPD (47.2 vs 64%, P<0.001) and death (13.8 vs 32.9%, P<0.001) rate were similarly lower in the EPWL group. The risk-adjusted odds ratios (ORs) showed that EPWL was associated with lower rate of death or BPD (OR 0.47, 95% CI: 0.37-0.60). In SGA infants, on univariate analysis, a similar association between EPWL and outcomes was seen as shown in AGA infants: death or BPD (55.9 vs 75.2%, P<0.001), BPD rate (48.3 vs 62.1%, P=0.002) and rate death (19 vs 40.8%, P<0.001) for those with or without EPWL, respectively. Multiple logistic regression showed that as in AGA ELBW infants, EPWL was associated with lower risk for death or BPD (OR 0.60, 95% CI: 0.41-0.89) among SGA infants. CONCLUSIONS: SGA infants experienced less EPWL when compared with their AGA counterparts. EPWL was associated with a lower risk of death or BPD in both ELBW AGA and SGA infants. These data suggest that clinicians who consider the association between EPWL and risk of death or BPD should do so independent of gestation/birth weight status.
Subject(s)
Bronchopulmonary Dysplasia/epidemiology , Infant, Small for Gestational Age , Infant, Very Low Birth Weight , Weight Loss , Bronchopulmonary Dysplasia/etiology , Bronchopulmonary Dysplasia/mortality , Cohort Studies , Databases, Factual , Female , Gestational Age , Humans , Incidence , Infant Mortality , Infant, Newborn , Male , Prevalence , Retrospective Studies , United States/epidemiologyABSTRACT
OBJECTIVE: Inhaled nitric oxide (iNO) use in infants >1500 g, but <34 weeks gestation with severe respiratory failure will reduce the incidence of death and/or bronchopulmonary dysplasia (BPD). STUDY DESIGN: Infants born at <34 weeks gestation with a birth weight >1500 g with respiratory failure were randomly assigned to receive placebo or iNO. RESULTS: Twenty-nine infants were randomized. There were no differences in baseline characteristics, but the status at randomization showed a statistically significant difference in the use of high-frequency ventilation (P=0.03). After adjustment for oxygenation index entry strata, there was no difference in death and/or BPD (adjusted relative risk (RR) 0.80, 95% confidence interval (CI) 0.43 to 1.48; P=0.50), death (adjusted RR 1.26, 95% CI 0.47 to 3.41; P=0.65) or BPD (adjusted RR 0.40, 95% CI 0.47 to 3.41; P=0.21). CONCLUSIONS: Although sample size limits our ability to make definitive conclusions, this small pilot trial of iNO use in premature infants >1500 g and <34 weeks with severe respiratory failure suggests that iNO does not affect the rate of BPD and/or death.
Subject(s)
Bronchopulmonary Dysplasia/prevention & control , Infant, Very Low Birth Weight , Nitric Oxide/therapeutic use , Respiratory Distress Syndrome, Newborn/drug therapy , Administration, Inhalation , Bronchopulmonary Dysplasia/etiology , Female , Gestational Age , Humans , Infant, Newborn , Male , Nitric Oxide/administration & dosage , Pilot Projects , Respiration, Artificial , Respiratory Distress Syndrome, Newborn/complications , Respiratory Distress Syndrome, Newborn/pathology , Severity of Illness Index , Treatment OutcomeABSTRACT
BACKGROUND: Previous studies have suggested that there is an increase in cardiac events in the morning. Fewer data relate cardiac events to months of the year and season. METHODS AND RESULTS: We analyzed all monthly death certificate data from Los Angeles County, California, for death caused by coronary artery disease from 1985 through 1996 (n=222 265). The mean number of deaths was highest in December at 1808 and January at 1925; the lowest rates were in June, July, August, and September at 1402, 1424, 1418, and 1371, respectively. December and January had significantly higher rates than would be expected from a uniform distribution of monthly deaths (P=0.00001). The percent of yearly coronary deaths was defined by the quadratic U-shaped equation [percent=13.1198-1.5238(month)+0. 0952(month(2)), where January=1, February=2, etc]. When monthly deaths were plotted by year, there was a decrease from 1985 through 1996. Monthly mortality correlated inversely with temperature. During the months with the highest frequency of death (December, January), however, there was an increase in deaths that peaked around the holiday season and then fell, which could not be explained solely on the basis of the daily temperature change. CONCLUSIONS: Even in the mild climate of Los Angeles County, there are seasonal variations in the development of coronary artery death, with approximately 33% more deaths occurring in December and January than in June through September. Although cooler temperatures may play a role, other factors such as overindulgence or the stress of the holidays might also contribute to excess deaths during these peak times.
Subject(s)
Coronary Disease/mortality , Seasons , Climate , Coronary Disease/classification , Death Certificates , Holidays , Humans , Light , Los Angeles/epidemiology , Risk , Stress, Physiological/epidemiology , TemperatureABSTRACT
OBJECTIVES: We sought to determine whether a natural disaster affected total cardiovascular mortality and coronary mortality in an entire population. BACKGROUND: The effect of the January 17, 1994 Northridge Earthquake (NEQ) on all deaths and causes of deaths within the entire population of Los Angeles County is unknown. The purposes of our study were to analyze all deaths in this entire population before, during and after the NEQ and to determine whether the NEQ temporally and spatially altered death due to cardiovascular disease. METHODS: We analyzed all death certificate data (n = 19,617) from Los Angeles County during January of 1992, 1993 (control periods) and 1994, using International Classification of Diseases, 9th Revision codes for ischemic heart disease (IHD) and atherosclerotic cardiovascular disease (ASCVD), as well as other causes of death. RESULTS: There was an average of 73 deaths per day due to IHD and ASCVD during January 1 to 16, 1994; this increased to 125 on the day of the NEQ, and then decreased to 57 deaths per day from January 18 to 31 (p < 0.00001, before NEQ vs. day of NEQ; after NEQ vs. day of NEQ; and before NEQ vs. after NEQ). The NEQ was associated with an increase in deaths due to myocardial infarction and trauma but not cardiomyopathy, hypertensive heart disease, valvular heart disease, cerebrovascular disease or noncardiovascular causes. Based on plots of daily deaths due to IHD and ASCVD, the decrease in deaths during the 14 days after the NEQ (-144) overcompensated for the increase on the day of the NEQ (+55). Geographic analysis revealed a redistribution of deaths due to IHD and ASCVD toward the epicenter on the day of the NEQ. CONCLUSIONS: When an entire population simultaneously experiences a major environmental stress, there is an increase in death due to coronary artery disease (but not other cardiac causes), followed by a decrease that overcompensates for the excess of death. The overcompensation may represent a residual population that is more resistant to stress or a possible preconditioning effect of the stress, or both. This study supports the concept that cardiovascular events within an entire population can be triggered by a shared stress.
Subject(s)
Cardiovascular Diseases/mortality , Disasters , Aged , Aged, 80 and over , California/epidemiology , Cardiomyopathies/mortality , Cerebrovascular Disorders/mortality , Female , Heart Valve Diseases/mortality , Humans , Hypertension/mortality , Incidence , Male , Middle Aged , Myocardial Ischemia/mortality , Retrospective Studies , Stress, Physiological/mortalityABSTRACT
During the 3-day period of the Los Angeles riots in 1992, there was a significant increase in the total number of deaths investigated by the Coroner's office and deaths attributed to violence and trauma, but not to atherosclerotic cardiovascular mortality. However, there was a significant decrease in cardiovascular mortality in the period following the riots, compared with the period of the riots or the preceding period.
Subject(s)
Arteriosclerosis/mortality , Death, Sudden, Cardiac/epidemiology , Riots , Violence , Coroners and Medical Examiners , Death, Sudden, Cardiac/etiology , Female , Humans , Los Angeles/epidemiology , MaleABSTRACT
Although the use of composite end points in clinical trials has increased in recent years, few data are available on the validity of such an approach. In the Thrombolysis In Myocardial Infarction (TIMI) 4 and 5 trials, we set out to validate prospectively the nonfatal components of the "unsatisfactory outcome" end point. This end point consisted of the in-hospital occurrence or observation of new-onset severe congestive heart failure/shock, left ventricular ejection fraction <40% (or <30% for patients with prior myocardial infarction), reinfarction, reocclusion by sestamibi perfusion imaging, TIMI flow grade <2 at 90 minutes or 18 to 36 hours, intracranial hemorrhage, major spontaneous hemorrhage, or anaphylaxis. Among 576 patients in TIMI 4 and 5 with 1-year follow-up, a nonfatal unsatisfactory outcome end point was reached in hospital in 45% of patients. Compared with patients without such an end point, patients with an end point had a relative risk of 1-year mortality of 2.5 (95% confidence interval 1.4 to 5.6, p = 0.001). For individual components, new-onset severe congestive heart failure/shock had a relative risk of 4.6 (p = 0.001), left ventricular ejection fraction <40% had a relative risk of 3.5 (p = 0.006), recurrent myocardial infarction had a relative risk of 2.2 (p = 0.047), and TIMI flow grade <2 at 90 minutes had a relative risk of 2.2 (p = 0.005). Our findings show that these nonfatal in-hospital end points and the composite end point are associated with an increased risk of 1-year mortality and as such are valid predictive survival markers for use in clinical trials.
Subject(s)
Heart Diseases/mortality , Myocardial Infarction/drug therapy , Treatment Outcome , Aged , Clinical Trials as Topic/methods , Fibrinolytic Agents/therapeutic use , Heart Failure/etiology , Hemodynamics , Hirudin Therapy , Humans , Middle Aged , Myocardial Infarction/complications , Myocardial Infarction/mortality , Plasminogen Activators/therapeutic use , Prognosis , Prospective Studies , Recurrence , Reproducibility of Results , Risk , Thrombolytic Therapy , Ventricular Dysfunction, Left/etiologyABSTRACT
Although the association between heavy alcohol use and HIV risk has been studied in treatment populations, we know little about patterns of alcohol use and HIV risk among out-of-treatment African-American drug users. This study examines the extent to which alcohol use affects HIV risk in a sample of 495 African-American crack users who did not inject drugs. We present differences between levels of alcohol and crack use with regard to sexual practices (including sex while impaired), number of partners, frequency of sexual activity, and condom use. The findings suggest an intimate relationship between alcohol use, crack use, and sexual risks for HIV infection. Respondents who reported frequent use (15-30 days in the last 30 days) of alcohol, crack, or both displayed significantly greater risk than those who reported less than frequent use.
Subject(s)
Alcoholism/epidemiology , Black or African American/psychology , Cocaine-Related Disorders/epidemiology , Crack Cocaine , HIV Seropositivity/epidemiology , Adolescent , Adult , Aged , Alcoholism/complications , Cocaine-Related Disorders/complications , Female , HIV Seropositivity/complications , Humans , Male , Middle Aged , Risk Factors , Sexual Behavior/psychologyABSTRACT
The National Human Exposure Assessment Survey (NHEXAS) provides a rich database of exposure and environmental measurements for persons living in EPA Region V (Great Lakes). Demographics (e.g., gender, minority status, age, income, and year home built) between U.S. Census data and the overall Region V sample were compared and showed good agreement. This representative sample was used to conduct an exploratory investigation of selected subpopulations that might exhibit higher exposures, on average, to volatile organic chemicals (VOCs) such as benzene, chloroform, etc.; inspirable particles; and metals (e.g., lead, arsenic, etc.) than the general population in Region V. Means and medians were the metrics of comparison. Personal air exposures for p-dichlorobenzene were significantly higher in adults (> 21 years old) than in children (1-14 years old) (median: below detection limit vs. 0.87 microgram/m3, p = 0.0005), while a trend toward higher levels of arsenic exposure in children than adults was observed (median: 1.13 vs. 0.8 ng/m3, p = 0.083). A trend towards higher personal air exposure to lead for minorities vs. nonminorities was evident (median: 26 vs. 12 ng/m3, p = 0.066), but personal exposure to 1,1,1-trichloroethane tended to be higher in nonminorities (mean: 22 vs. 3.7 micrograms/m3, p = 0.081). Dietary exposure to arsenic from solid foods was significantly higher in adults than children (mean: 21 vs. 7.1 micrograms/kg, p = 0.0001; median: 10 vs. 5.6 micrograms/kg, p = < 0.001), and for cadmium it was higher for nonminorities than minorities (median: 18 vs. 15 micrograms/kg, p = 0.023). In contrast, the dietary intake for arsenic, which is based on body weight, was significantly higher in children than adults (mean: 1.72 vs 1.38 micrograms/kg-1 day-1, p = < 0.0001; median 1.02 vs. 0.83, p = < 0.0001). Dietary exposure to chromium in beverages tended to be higher in minorities than nonminorities (median: 16 vs. 13 micrograms/kg, p = 0.017). Lead levels in surface dust wipes tended to increase with the age of the home (mean: 128 micrograms/g in homes built since 1980 to 1075 micrograms/g in homes built before 1940; median: 93 to 236 micrograms/g, respectively). These findings were consistent with the observation that for persons living in older homes personal air exposures to lead are elevated compared to persons living in recently built homes (median: 12 ng/m3 in homes built since 1980, vs. 24 ng/m3 in homes built before 1940, p = 0.043).
Subject(s)
Air Pollution/analysis , Environmental Exposure/analysis , Health Surveys , Lead/analysis , Organic Chemicals/analysis , Adolescent , Adult , Aged , Censuses , Child , Child, Preschool , Databases, Factual , Demography , Diet , Female , Food Contamination , Great Lakes Region , Housing , Humans , Infant , Infant, Newborn , Male , Middle AgedABSTRACT
Several volatile organic compounds, including tetrachloroethylene, have been found to be nearly ubiquitous in residential indoor environments during previous TEAM studies. Eleven homes in New Jersey were monitored over three or five days to examine the effect of bringing freshly dry-cleaned clothes into the home on indoor air levels and personal exposures to tetrachloroethylene. Indoor air, personal air, and breath concentrations were measured over multiple 12-hrs periods before and after dry-cleaned clothes were introduced into nine of the homes. No dry-cleaned clothes were introduced into the two remaining homes. Outdoor air tetrachloroethylene concentrations were measured at six of the eleven homes. Indoor/outdoor concentration ratios and source strengths were calculated at the six homes with outdoor measurements. Elevated indoor air levels and human exposures to tetrachloroethylene were measured at seven of the nine homes with dry-cleaned clothes. Indoor air concentrations reached 300 micrograms/m3 in one home and elevated indoor levels persisted for at least 48 hrs in all seven homes. Indoor/outdoor tetrachloroethylene concentration ratios exceeded 100 for the four homes with both dry-cleaned clothes and outdoor measurements. Maximum source strengths ranged from 16 to 69 mg/hr in these homes and did not directly correspond to the number of dry-cleaned garments brought into the home. Breath levels of tetrachloroethylene increased two to six-fold for participants living in seven homes with increased indoor air levels. Indoor air, personal air, and breath tetrachloroethylene concentrations were significantly related (0.05 level) to the number of garments introduced divided by the home volume.
Subject(s)
Air Pollutants/analysis , Air Pollution, Indoor/analysis , Clothing/adverse effects , Tetrachloroethylene/analysis , Breath Tests , Environmental Monitoring , Housing , Humans , New Jersey , United States , United States Environmental Protection AgencyABSTRACT
The National Human Exposure Assessment Survey (NHEXAS) Phase I field study conducted in EPA Region 5 provides extensive exposure data on approximately 250 study participants selected via probability sampling. Associated environmental media and biomarker (blood, urine) concentration data were also obtained to aid in the understanding of relationships of the exposures to both contaminant sources and doses. Distributional parameters for arsenic (As), lead (Pb), and four volatile organic compounds (VOCs)--benzene, chloroform, tetrachloroethylene, and trichloroethylene--were estimated for each of the relevant media using weighted data analysis techniques. Inter-media associations were investigated through correlation analysis, and longitudinal correlations and models were used to investigate longitudinal patterns. Solid food appeared to be a major contributor to urine As levels, while Pb levels in household (HH) dust, personal air, and beverages all were significantly associated with blood Pb levels. Relatively high (>0.50) longitudinal correlations were observed for tap water Pb and As, as compared to only moderate longitudinal correlations for the personal air VOCs.
Subject(s)
Arsenic/metabolism , Benzene/metabolism , Environmental Exposure/analysis , Hydrocarbons, Chlorinated/metabolism , Lead/metabolism , Chloroform/metabolism , Confidence Intervals , Great Lakes Region , Humans , Lod Score , Longitudinal Studies , Tetrachloroethylene/metabolism , Trichloroethylene/metabolismABSTRACT
Particle concentrations were measured for a probability-based sample of 178 nonsmoking individuals aged 10 or older residing in Riverside, California, in the fall of 1990. Two 12-hr personal-exposure PM10 samples were obtained for each participant, along with fixed-location PM10 and PM2.5 indoor and outdoor air samples at their residences. The particle samples were also analyzed via X-ray fluorescence (XRF) to determine elemental concentrations for selected elements, including some toxic metals, crustal elements, and combustion- and industrial-source related elements. About 25% of the target population was estimated to have 24-hr personal exposures to PM10 that exceeded the national ambient air concentration standard of 150 micrograms/m3. The daytime personal exposure levels (median of 130 micrograms/m3) tended to exceed both indoor and outdoor levels by about 50%; nighttime personal exposure levels were lower and were only slightly higher than nighttime indoor levels. Several possible reasons for the elevated daytime personal PM10 levels (relative to indoor levels) are considered. Certain activities such as house cleaning and smoking were found to be associated with elevated personal exposure levels.
Subject(s)
Air Pollution, Indoor/analysis , Air Pollution/analysis , Environmental Monitoring/methods , Aerosols , California , Humans , Occupational Exposure , Smoke/analysis , Smoking/adverse effects , Specimen Handling , Vehicle Emissions/analysisABSTRACT
The U.S. Environmental Protection Agency's (EPA) previous TEAM studies of personal exposure to VOCs for 700 residents in several U.S. cities found that indoor air concentrations were often higher than outdoor levels. Several potential sources of benzene exposure were identified, including environmental tobacco smoke and materials or activities associated with attached garages. Indoor, personal, and outdoor monitoring was conducted at eleven New Jersey homes over multiple 12-hr monitoring periods. One study objective was to assess the impact of attached garages on human exposure to benzene and the variability of benzene exposure across time. Benzene was also measured in several homes inhabited by smokers and in homes without known combustion sources for comparative purposes. At homes with a garage or environmental tobacco smoke, mean indoor and personal benzene concentrations were two to five times higher than outdoor levels at all but one home. Mean personal exposures ranged from 8 to 31 micrograms/m3. Indoor/outdoor ratios were calculated and ranged from 0.8 to 11. Benzene levels in the four garages ranged from 3 to 196 micrograms/m3 and usually were higher than either indoor living areas or personal levels. Multi-zone air exchange rates were measured, and benzene source strengths in each zone were estimated. Garage source strength estimates for benzene ranged from 310 to 52,000 micrograms/h. The mass transfer of benzene from sources in the garage to home living areas was also large in three of the homes, ranging from 730 to 26,000 micrograms/h. Materials or activities in the garage were a source of benzene exposure for the residents in these three homes. Large temporal variations (factors of 2 to 30) were observed in indoor and personal benzene concentrations, indoor/outdoor ratios, and source strengths over the six or ten monitoring periods at each home. Changes in outdoor air benzene levels were an underlying factor in changing exposure levels, with indoor sources further elevating indoor air levels and personal exposures.
Subject(s)
Air Pollution, Indoor/analysis , Benzene/analysis , Environmental Exposure/analysis , Housing , Tobacco Smoke Pollution/analysis , Vehicle Emissions/analysis , Humans , New Jersey , Time FactorsABSTRACT
The U.S. Environmental Protection Agency and the California Air Resources Board studied the exposures of 51 residents of Los Angeles, California, to 25 volatile organic chemicals (VOCs) in air and drinking water in 1987. A major goal of the study was to measure personal, indoor, and outdoor air concentrations, and breath concentrations of VOCs in persons living in households that had previously been measured in 1984. Other goals were to confirm the marked day-night and seasonal differences observed in 1984; to determine room-to-room variability within homes; to determine source emission rates by measuring air exchange rates in each home; and to extend the coverage of chemicals by employing additional sampling and analysis methods. A total of 51 homes were visited in February of 1987, and 43 of these were revisited in July of 1987. The results confirmed previous TEAM Study findings of higher personal and indoor air concentrations than outdoor concentrations of all prevalent chemicals (except carbon tetrachloride); higher personal, indoor, and outdoor air concentrations in winter than in summer; and (in winter only) higher outdoor concentrations at night than in the daytime. New findings included the following: (1) room-to-room variability of 12-hour average concentrations was very small, indicating that a single monitor may be adequate for estimating indoor concentrations over this time span; (2) "whole-house" source emission rates were relatively constant during both seasons, with higher rates for odorous chemicals such as p-dichlorobenzene and limonene (often used in room air fresheners) than for other classes of chemicals; (3) breath concentrations measured during morning and evening were similar for most participants, suggesting the suitability of breath measurements for estimating exposure in the home; (4) limited data obtained on two additional chemicals-toluene and methylene chloride-indicated that both were prevalent at fairly high concentrations and that indoor air concentrations exceeded outdoor concentrations by a factor of about three.
Subject(s)
Air Pollutants/analysis , Air Pollution, Indoor/analysis , Breath Tests/methods , Adolescent , Adult , Aged , Aged, 80 and over , Child , Environmental Monitoring , Female , Humans , Los Angeles , Male , Middle Aged , United States , United States Environmental Protection Agency , Water Pollutants, Chemical/analysisABSTRACT
Results are presented from a statewide survey that measured annual 222Rn concentrations in over 2000 single-family, owner-occupied homes in New York state. The participants were selected by a random-digit-dialing telephone interview approach developed by Mitofsky-Waksberg which allows inferences to be made from the sample to the statewide population. After completing a telephone questionnaire and agreeing to have their homes monitored, eligible households were mailed alpha-track detectors with instructions to place one detector in the main living area for 2 mo (during the winter heating season), a second in the main living area for 1 y, and a third in the basement (if applicable) for 1 y. The statewide median concentration for the heating-season, living-area readings was 31.6 Bq m-3, with a median of 24.0 Bq m-3 for the annual living-area readings and 51.8 for the annual basement readings. For the state, approximately 95% of the living-area concentrations and 86% of the basement concentrations were below 148 Bq m-3 (4 pCi L-1). In addition, only 1.4% of the readings in the basement were above 740 Bq m-3 (20 pCi L-1).
Subject(s)
Housing , Radioactive Pollutants/analysis , Radon/analysis , Heating , New York , Radiation Monitoring/methods , Random AllocationABSTRACT
Personal exposures and breath concentrations of approximately 20 volatile organics were measured for 200 smokers and 322 nonsmokers in New Jersey and California. Smokers displayed significantly elevated breath levels of benzene, styrene, ethylbenzene, m + p-xylene, o-xylene, and octane. Significant increases in breath concentration with number of cigarettes smoked were noted for the first four aromatic compounds. Based on direct measurements of benzene in mainstream cigarette smoke, it is calculated that a typical smoker inhales 2 mg benzene daily, compared to 0.2 mg/day for the nonsmoker. Thus, cigarette smoking may be the most important source of exposure to benzene for about 50 million citizens of the United States. Passive smokers exposed at work had significantly elevated levels of aromatics in their breath. Indoor air levels in homes with smokers were significantly greater than in nonsmoking homes during fall and winter but not during spring and summer. The average annual increase in homes with smokers was 3.6 microgram/m3 for benzene and 0.5 microgram/m3 for styrene--an approximate 50% relative increase in each case. Thus, exposure to benzene and styrene may be increased for the approximately 60% of children and other nonsmokers living in homes with smokers.