Air Pollution and Health: An introduction Ferran Ballester

Unit of Epidemiology & Statistics Valencian School of Studies for Health-EVES Air pollution projects involved: APHEA APHEIS EMECAS

Literature There are many articles and books on air pollution and health There are also useful resources in Internet.

OBJECTIVES: Introduce the basic concepts on air pollution and health Comment on the most used epidemiological designs Present the results of some of the main studies carried out in recent years

Hippocrates

–Meuse Valley, Belgium (1930) –Donora, Pennsilvania, USA (1948) –London, UK (1952) Air Pollution Major Episodes in the mid XX th century

The London Fog

December ,000 0,500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 4,500 5,000 Black Smoke Central Hall mg/m3 Daily deaths, London

Anual average of black smoke (in  g/m 3 ) London

Major emission sources of air pollutants SO 2 VOCsNO X PM Power Generation Domestic Dwellings Industry Pb Stationary Emission Sources CO VOCs NO X Pb Petrol PM Diesel Mobile Emission Sources (Road Traffic)

Major Air Pollutants (1)

Major Air Pollutants (2)

Health Effects of Air Pollution Mortality Cardiopulmonary Hospitalizations Emergency department or outpatient visits Symptomatic exacerbations Changes in lung function Cardiopulmonary symptoms Upper respiratory illnesses Lower respiratory illnesses

Other Effects of Air Pollution Immune System; Allergies Allergic Asthma, Allergic Rhinoconjunctivitis Extrinsic Allergic Alveolitis / Hypersensitivity Central Nervous System Toxic Damage of Nerve Cells Mental retardation Carcinogenic Effects Lung Cancer, Leukemia Reproductive effects Infant mortality, Low weight birth

Annoyance, discomfort Symptoms Medication Restricted activity Visits to doctors Emergencies Hospitalizations Deaths Number of persons concerned ADVERSE HEALTH EFFECTS

Health effect assessment Toxicological studies Epidemiological studies

Basic study designs in air pollution epidemiology Exposure Unit of observation AcuteChronic AggregatedTime Series (counts): Mortality, Hospital Admissions Emergencies Episodes, interventions Ecological (rates): Mortality Morbidity Cross-sectional IndividualPanel studies: Symptoms/Diseases Lung Function Cohort studies Cohort studies: Mortality Symptoms/Disease Lung Function Cross-sectional

Exposure assesment approaches in epidemiology of air pollution Categorical exposure (high vs low) Measured (or modeled) outdoor concentrations Measurement of indoor and outdoor concentrations Estimation of individual exposure using indoor, outdoor along time-activity diaries Direct measurement of personal exposures Measurement of biomarkers of exposure COST VALIDITY

Results from some epidemiological studies Time series Cohort studies Intervention studies

Relationship between the factors implied in the time series epidemiological studies of air pollution

APHEA1 cities Population > 25,000,000

APHEA1 FINDINGS 1.All pollutants studied have small acute effects on the daily total, cardiovascular and respiratory mortality. 2.Particulates and ozone levels were consistently associated with respiratory and COPD admissions. 3.NO2 levels were associated with asthma admissions. 4.The effects were observed in locations where, in the majority of days, air pollutant levels were well below the set (W.H.O., E.C., U.S.E.P.A.) standards at that time.

APHEA2 EC Funded 30 cities 43 million inhabitants Period of study: 5 years (~ )

The EMECAS Project

EMECAS: Combined estimates for mortality and air pollution (1)

NO2_24hCO_24h % change -2,0 -1,0 0,0 1,0 2,0 3,0 4,0 5,0 6,0 TOTAL CVS RES EMECAS: Combined estimates for mortality and air pollution (2)

EMECAS: combined results for cardiovascular admissions

Harvard Six-City Cohort Study Relative risk of mortality and long- term exposure to PM2.5 Dockery et al, 1993 RR Annual mean PM2.5 (  g /m 3 )

1.01 ( )Other causes 1.14 ( )Lung cancer 1.09 ( )Cardiopulmonary 1.06 ( )Total mortality RR (  10µg/m 3 ) Cause of death Long-term exposure to fine particulates and mortality in the ACS cohort (n: ) Pope et al, 2002

Long term effects in mortality and indicators of traffic-related air pollution in the Netherlands Hoek et al, 2002 Cardio pulmonary Non-Cardio pulmonary Non-lung cancer Black smoke 1.34 ( ) 1.15 ( ) Major road 1.95 ( ) 1.03 ( )

Close of a steel mill in the Utah Valley:  particle levels,  morbidity,  inflammatory process Ban on marketing and sale of smoky coal in Dublin:  black smoke levels,  mortality Introduction of gas with low sulphur in Hong Kong:  levels of SO2 and SO4,  mortality and respiratory symptoms in children Intervention studies

Summary of estimates of particulate matter effects (1)

Summary of estimates of particulate matter effects (2)

Summary Main acute effects: –Increase in the number of deaths –Increase in hospital admissions and emergency visits, especially for cardio- respiratory causes –Alterations in lung performance, cardiac problems and other symptoms and discomfort Main chronic effects: –Increase in the risk of death –Increased cardio-respiratory morbidity and decline of pulmonary function

References