9 research outputs found
Airborne Endotoxin Is Associated with Respiratory Illness in the First 2 Years of Life
To determine the influence of endotoxin on the incidence of acute respiratory illness during the first 2 years of life, we carried out a longitudinal follow-up study, beginning at birth, of 332 children born in Prince Edward Island, Canada. We measured 5-day averaged air endotoxin in the homes of children, whose parents provided information by daily symptom diaries and twice-monthly telephone contact for up to 2 years. Endotoxin concentration was 0.49 ± 3.49 EU/m(3) (geometric mean ± geometric SD), and number of annualized illness episodes was 6.83 ± 2.80 (mean ± SD). A doubling of the air endotoxin concentration was associated with an increase of 0.32 illness episodes per year (p = 0.0003), adjusted for age, year of study, breast-feeding, environmental tobacco smoke, child care attendance, indoor temperature, and income. Indoor mold surface area and fungal ergosterol were not significantly associated with endotoxin. Airborne endotoxin appears to be a risk factor for clinically symptomatic respiratory illnesses during the first 2 years of life independent of indoor fungus
Association of the Frequency of Respiratory Illness in Early Childhood with a Change in the Distribution of Blood Lymphocyte Subpopulations
Little is known about the distribution of lymphocyte phenotypes in young children and the association specific phenotypes may have with respiratory illnesses. The objective of this study was to describe lymphocyte distributions in children at approximately 2 years of age and to test for associations with the frequency of respiratory illness during the first 2 years of life. We hypothesized that an increased frequency of illness would be associated with those phenotypes that reflect previous antigen exposure and/or immune activation. Seventy-three children were followed during their first 2 years of life with daily symptom diaries and twice-monthly telephone calls to ascertain the incidence of respiratory illness. After the children reached 2 years of age, the phenotypes of circulating blood lymphocytes were measured by flow cytometry. Associations between illness and phenotypes were adjusted for education level of parents; hours per week in day care; hours per week exposed to environmental tobacco smoke, mould, or water damage in bedroom; and parental history of allergy and asthma. The resulting median lymphocyte count was 4.0 × 109 per litre (standard deviation, 1.3) with a CD4/CD8 count of 2.28, consistent with published values. Illness rates were positively associated with the percentage of CD8+ CD38+ T cells (unadjusted p = .03, adjusted p = .014), CD8+ CD45RO+ T cells (unadjusted p = .06, adjusted p = .036), and CD4+ CD45RO+ T cells (unadjusted p = .01, adjusted p = .005). Our conclusions is that there is an association between the distribution of lymphocyte phenotypes and the incidence of respiratory illness early in life. Future research is recommended to determine the directionality of this association
Association of the Frequency of Respiratory Illness in Early Childhood with a Change in the Distribution of Blood Lymphocyte Subpopulations
Abstract Little is known about the distribution of lymphocyte phenotypes in young children and the association specific phenotypes may have with respiratory illnesses. The objective of this study was to describe lymphocyte distributions in children at approximately 2 years of age and to test for associations with the frequency of respiratory illness during the first 2 years of life. We hypothesized that an increased frequency of illness would be associated with those phenotypes that reflect previous antigen exposure and/or immune activation. Seventy-three children were followed during their first 2 years of life with daily symptom diaries and twice-monthly telephone calls to ascertain the incidence of respiratory illness. After the children reached 2 years of age, the phenotypes of circulating blood lymphocytes were measured by flow cytometry. Associations between illness and phenotypes were adjusted for education level of parents; hours per week in day care; hours per week exposed to environmental tobacco smoke, mould, or water damage in bedroom; and parental history of allergy and asthma. The resulting median lymphocyte count was 4.0 × 109 per litre (standard deviation, 1.3) with a CD4/CD8 count of 2.28, consistent with published values. Illness rates were positively associated with the percentage of CD8+ CD38+ T cells (unadjusted p = .03, adjusted p = .014), CD8+ CD45RO+ T cells (unadjusted p = .06, adjusted p = .036), and CD4+ CD45RO+ T cells (unadjusted p = .01, adjusted p = .005). Our conclusions is that there is an association between the distribution of lymphocyte phenotypes and the incidence of respiratory illness early in life. Future research is recommended to determine the directionality of this association.</p
Economic evaluation of the benefits of reducing acute cardiorespiratory morbidity associated with air pollution
Background:
Few assessments of the costs and benefits of reducing acute cardiorespiratory morbidity related to air pollution have employed a comprehensive, explicit approach to capturing the full societal value of reduced morbidity.
Methods:
We used empirical data on the duration and severity of episodes of cardiorespiratory disease as inputs to complementary models of cost of treatment, lost productivity, and willingness to pay to avoid acute cardiorespiratory morbidity outcomes linked to air pollution in epidemiological studies. A Monte Carlo estimation procedure was utilized to propagate uncertainty in key inputs and model parameters.
Results:
Valuation estimates ranged from 0–28) for avoidance of an acute respiratory symptom day to 4,000–1.4 million (95% confidence interval $0.91–1.8 million) in relation to reduced emergency department visits and hospital admissions for cardiorespiratory disease.
Conclusion:
Our approach to estimating the value of avoiding a range of acute morbidity effects of air pollution addresses a number of limitations of the current literature, and is applicable to future assessments of the benefits of improving air quality.Health Care and Epidemiology, Department ofNon UBCMedicine, Faculty ofReviewedFacult