Long term effects of air pollution on health

Long term effects of air pollution on health. Peter Burney. King’s College London

Breathlessness by night or day by annual mean PM 10 (Sepaldia) • Selected symptoms associated with measures of air pollution • Some correlations work out better than others

Proportion of the non-smoking population with FVC < 70% by TSP (NHANES) • Continuous increase in poor lung function as particulate levels rise. • Adjusted for age, height, sex, race, obesity, occupation, temperature, income and region

The Meaning of Chronic Morbidity • Repeated acute effects? • Change in susceptibility? • Irreversible changes?

Changes in lung function in different communities (Tashkin 1994) Relative decline in FEV 1 (ml) Lancaster Long Beach Glendora TSP (mg/m 3) 85 101 133 MEN 0 -18. 4* -26. 5** WOMEN 0 -15. 6** -16. 2** Adjusted for age, height, initial FEV 1, allergy and smoking *p<0. 01; **p<0. 001

Differences in lung function growth between ‘polluted’ and ‘unpolluted’ areas (from Jedrychowski, et al. 1999)

Factors predicting adult respiratory disease in the 1946 national birth cohort (Mann et al, 1992)

SMR from bronchitis related to area based infant mortality from LRTI • Area SMR from bronchitis is associated with infant mortality from pneumonia 70 years earlier.

Possible causes of inconsistency • • Various outcomes Various exposures Modifying factors Measurement errors • • Bronchitis COPD Allergy Asthma Cancer Early infection Premature birth

Possible causes of inconsistency • • Various outcomes Various exposures Modifying factors Measurement errors • • • Particles SO 2 NO 2 Oxidants ‘Traffic’ Diesel

Lorry traffic affects infant lung disease in metropolitan but not urban or rural areas (Ciccone et al. , 1998)

Effect of supplementing cyclists with antioxidants on the respiratory response to ozone (from Grievink et al. 1998)

Prospects • The evidence is currently descriptive. • The evidence is reported inconsistently. • There is likely to be reporting bias. • Much of the data refers to pollution patterns that are now largely historic.

ECRHS II • A follow-up of subjects studied in ECRHS I • A study of many different protocols linked to studying aetiology and prognosis • Principal outcomes relate to atopy, asthma, lung function and bronchial hyperresponsiveness • Some specific protocols on air pollution

ECRHS II centres

ECRHS II pollution protocols • • • Historic review of air pollution data Measurement of PM 2. 5 in all centres Analysis of PM 2. 5 for metal content Measurement of dust mite allergen from beds Measurement of NO 2 from kitchens, outside kitchen windows and at central monitor in selected centres

ECRHS II Analysis principally relates to the natural history (incidence, remission and modification of disease over time) of asthma, atopy, lung function, and airway responsiveness.

ECRHS II The major strengths of the study are its size, the diversity of the environments studied, the extent of the potential confounders being assessed.