Epidemiologic studies on health effects of air pollution in

Japan

Masayuki Shima島 正之

Hyogo College of Medicine, Japan兵庫医科大学

Outlines

Air pollution and its health effects in the past

Pollution control and its effects on human health

Present status of air pollution in Japan

Traffic-related air pollution and its health effects Epidemiologic study in Chiba Prefecture

Ongoing study by the Ministry of Environment (the SORA projects)

Air Pollution in the past in Japan

Yokkaichi Asthma Air pollution in the 1960s, due to petroleum complex in

Yokkaichi, Japan

Prevalence of bronchial asthma and chronic bronchitis increased among people living in the vicinity of the complex.

In Japan, from around 1960, the concentrations of air pollutants increased in many industrial cities, and health effects of air pollution had became a major concern in the cities, including Tokyo, Kawasaki, Chiba, Fuji, Osaka, Amagasaki, Kobe.

Areas with high levels of air pollution in the 1960s and 1970s in Japan

Yokkaichi

Fuji

Chiba

Amagasaki

Tokyo

Osaka

Yokohama, Kawasaki

Tokai, Nagoya

Kita-Kyushu

Omuta

Kurashiki, TamanoBizen Kobe

Concentrations of sulfur dioxide in Yokkaichi

YokkaichiConcentrations of sulfur dioxide（1964.11.24-27）

(Yoshida, et al. Arch Environ Health 13: 763-768, 1966)

Polluted areaNon-polluted area

Petrochemical plant

Prevalence of chronic bronchitis and COPD among adults in Yokkaichi

(Yoshida, et al. J Jpn Hyg, 22: 323-335, 1967)

Isozu

Polluted area Non-polluted area

Chronic Bronchitis

COPD

Pre

vale

nc

e (%

)

Sulfur oxides(mg/day)

Dust fall(ton/month)

Shiohama(north)

Shiohama(south)

Yogo Tomisuhara Sakura

Asthma and sulfur dioxide in Yokkaichi

(Yoshida, et al. Arch Environ Health 13: 763-768, 1966)

Relation between SO2 and yearly accumulated prevalence of asthma in 13 districts

Age group over 50 yr; April 1963 – March 1964

Relation between asthma attack and weekly average concentration of SO2

At Isozu 13 patientsJanuary to March 1963

r = 0.88

Concentrations of sulfur oxides in Fuji

（1972）

(Tani, et al. J Jpn Public Health, 22: 431-438, 1975）

Suruga Bay

Chronic bronchitis and sulfur dioxide

Adjusted prevalence of chronic bronchitis among adults aged ≥ 40 years

BMRC questionnaire

(Tani, et al. J Jpn Public Health, 22: 431-438, 1975）

Pre

vale

nc

e (%

)

Sulfur oxides

Concentrations of sulfur oxides in Chiba

(Motomiya, et al. J Jpn Public Health, 22: 397-402, 1975）

By PbO2 method, mg/100cm2/day（1972）

Steel mill (Tokyo Bay) Power station

Relationship between prevalence of asthma and sulfur oxides

Boys in 12 elementary schools（1972）

1971 1972 1971+1972

Pre

vale

nce

of a

sthm

a

Sulfur oxides Sulfur oxides Sulfur oxides

Pre

vale

nce

of a

sthm

a

Pre

vale

nce

of a

sthm

a

(Motomiya, et al. J Jpn Public Health, 22: 397-402, 1975）

Change in concentrations of sulfur oxides in Yokkaichi

(Imai, et al. Arch Environ Health 41: 29-35, 1986)

Annual average concentrations measured by the PbO2 method

Sulfur oxides levels and mortality due to respiratory diseases in Yokkaichi

(Imai, et al. Arch Environ Health 41: 29-35, 1986)

Age-adjusted mortalityTop：Bronchial asthma

Middle：Chronic bronchitis

Bottom：Annual averageconcentration of sulfuroxides

Concentrations of Sulfur Dioxide in Japan

0

0.01

0.02

0.03

0.04

0.05

0.06

0.07

1965 1970 1975 1980 1985 1990 1995 2000 2005

General environment Roadside

(ppm)Annual average concentrations

Concentrations of Nitrogen Dioxide in Japan

0

0.01

0.02

0.03

0.04

0.05

0.06

1970 1975 1980 1985 1990 1995 2000 2005

General environment Roadside

(ppm)Annual average concentrations

Concentrations of Suspended Particulate Matter (≤10m in diameter) in Japan

0.00

0.02

0.04

0.06

0.08

0.10

1975 1980 1985 1990 1995 2000 2005

General environment Roadside

(mg/m3)Annual average concentrations

Changes in Automobile Ownership(Number of Vehicles)

Passenger Automobiles

Trucks

Others(Buses, etc)

(10,000 Vehicles)

(Fiscal Year)

Changes in the problems of Air Pollution Industrial air pollution (factories, etc.)

→ Urban/Domestic air pollution（vehicles, etc.）

Gaseous pollutants → Particulate matters

Fine particles, Diesel exhaust particles, etc.

Uncontrolled toxic air pollutants

High concentrations→ Relatively low concentrations

Wide areas around factories→ Regional areas adjacent to major roads

Prevalence of bronchial asthma among Japanese children

0.0

1.0

2.0

3.0

4.0

5.0

1987 1990 1993 1996 1999 2002 2005 2008

Preschool Elementary school

Junior high school High school

(%)

(School Health Survey in Japan)

Health effects of automobile exhaust

Study subjects Children in 10 elementary schools

(about 6,000)Schools are located in urban areas, and their school districts are intersected by major trunk roads.

Schools are in rural areas, without major roads or factories.

Questionnaire for respiratory symptoms

Pulmonary function tests

Blood sampling for allergic and inflammatory tests

Measurements of indoor environments

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●●

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Epidemiologic study in Chiba Prefecture(1985～2000)

●●

○

○

○

●●

○

○

Prevalence of asthma

0

2

4

6

8

10

12

1992 1993 1994 1995 1992 1993 1994 1995

Males Females

Pre

vale

nce

(%)

0-49 m 50 m Rural areas

p = 0.026 p = 0.043†p = 0.022†

(Shima, et al. J Epidemiol, 13: 108-119, 2003)

≥

0

2

4

6

8

Males Females

Incid

ence (

%)

0-49 m

50 m

Rural areas

p = 0.013†

p = 0.158†

Incidence of asthma1992～1995

≥

(Shima, et al. J Epidemiol, 13: 108-119, 2003)

Incidence of wheeze

0

2

4

6

8

Males Females

Incid

enc

e (

%)

0-49 m

50 m

Rural areas

p = 0.347†

p = 0.893

Prevalence of wheeze

0

2

4

6

8

10

12

1992 1995 1992 1995

Males Females

Pre

val

ence

(%)

0-49 m

50 m

Rural areas

p = 0.038†

Prevalence and incidence of wheeze

³

≥≥

(Shima, et al. J Epidemiol, 13: 108-119, 2003)

Odds ratios for various factors on the incidence of asthma

Males Females

Areas 0-50 m 3.77 4.03

> 50 m 1.99 1.74

Rural areas 1.00 1.00

School grade, 1 grade increase 1.13 0.94

History of allergic diseases 2.95 6.03

Respiratory diseases before 2 yr 1.85 2.08

Breast feeding in infancy 1.42 0.60

Parental history of allergic diseases 2.82 1.20

Maternal smoking habits 1.74 2.15

House of steel or reinforced concrete 0.92 0.40

Use of unvented heaters in winter 1.47 0.77

Adjusted for all variables using logistic regression model

(Shima, et al. J Epidemiol, 13: 108-119, 2003)

Incidence of asthma by school grade

0

2

4

6

8

10

12

1st 2nd 3rd 4th 5th 6th

Ichikawa

Chiba

Funabashi

Kashiwa

Kisarazu

Ichihara

Tateyama

Mobara

Cum

ulat

ive

Inci

denc

e of

Ast

hma

(%)

FollowFollow--up from 1up from 1stst grade to 6grade to 6thth gradegrade

Urban districts

Rural districts

(Shima, et al. Arch Environ Health, 57: 529-535, 2002)

Incidence of asthma and outdoor nitrogen dioxide concentrations

(Shima, et al. Int J Epidemiol, 29: 862-870, 2000)

0.0

1.0

2.0

3.0

4.0

0 10 20 30 40

3-yr average outdoor nitrogen dioxide (ppb)

Incid

ence o

f ast

hm

a (

%)

r r 22 = 0.783= 0.783p = 0.008p = 0.008

(1992～1994)

Associations between incidence of asthma and concentrations of NO2 and SPM

0

2

4

6

8

10

12

0 10 20 30 40

Nitrogen Dioxide (ppb)

Inci

dence

of ast

hm

a (

%)

0

2

4

6

8

10

12

0 20 40 60

Suspended Particulate Matter(g/m3)

Inci

dence

of ast

hm

a (

%)

(Shima, et al. Arch Environ Health, 57: 529-535, 2002)

Measurement of Indoor nitrogen dioxide concentrations

The concentrations of indoor NO2 over 24 hours were measured in both the heating and non-heating periods in homes of pupils.

The badge type passivesamplers (Advantec,

Tokyo, Japan) were used.

Information on factors that could influence indoor environments was collected by questionnaire.

Indoor nitrogen dioxide concentrations

(Shima, et al. Occup Environ Med, 55: 428-433, 1998)

Odds ratios (OR) for various factors on the incidence of asthma

OR

Outdoor NO2 concentration, 0.01 ppm increase 2.10

Indoor NO2 concentration, 0.01 ppm increase 0.87

History of allergic diseases 7.96

Respiratory diseases before 2 yr 2.86

Breastfeeding in infancy 0.60

Parental history of allergic diseases 1.02

Maternal smoking habits 0.51

Use of unvented heaters in winter 1.26

Adjusted for all variables using logistic regression model

(Shima, et al. Int J Epidemiol, 29: 862-870, 2000)

Summary of epidemiologic study in Chiba, Japan

The prevalence and incidence of asthma increased among children living near major roads relative to rural areas.

The incidence rates of asthma were significantly increased with increases of outdoor NO2 concentrations.

Multiple logistic regression analysis showed that 10 ppb increase of outdoor NO2 concentrations was associated with an increased incidence of asthma (OR = 2.10).

These findings suggest that traffic-related air pollution may be of particular importance in the development of asthma among children living near major roads with heavy traffic.

Epidemiologic study on traffic-related air pollution in Japan

Background Many epidemiologic studies have shown associations

between traffic density and asthma prevalence or morbidity. However a few studies examine the relationship between asthma incidence and traffic-related exposures.

Well-designed studies are needed to assess the association between exposure to traffic-related air pollution and the onset of asthma and chronic respiratory diseases.

In view of this situation, the Japanese Ministry of the Environment has decided to launch the SORA projects (Study Of Respiratory diseases and Automobile exhaust).

Study On Respiratory disease and Automobile exhaust (SORA project)

① Cohort study of school children（2005～ ）

② Nested case control study of pre-school children（2006～ ）

③ Survey of respiratory symptoms and pulmonary function among adults（2007～ ）

＊http://www.env.go.jp/chemi/sora/

These studies are conducted to estimate the health effects of traffic-related air pollution in adjacent to major trunk roads in Japan.

“SORA” means sky in Japanese.

A school-based prospective cohort study have been conducted in the three metropolitan areas in Japan.

In fall 2005, we enrolled 16,300 children (grades 1-3) in 57 primary schools.

Of these schools, 49 schools are located in the districts with heavy traffic density (about 30,000-120,000 vehicles/day), and the other 8 schools are in the districts that were distant from major roads.

Cohort study among schoolchildren living along trunk roads

Schema of the study districts

Study subjects（ ）: 1st to 3rd schoolchildren (about 16,300)

Study area

Distant districts

Neighboring districts

School

Major roads with heavy traffic density (about 30,000-120,000 vehicles/day

Major road

Exhaust

School

School

Schedule of the study

Year 2005 2006 2007 2008 2009

Questionnaire surveyFall

(grades 1-3)

Fall (grades

2-4)

Fall (grades

3-5)

Fall (grades

4-6)

Fall (grades

5-6)

Blood samplingFall or winter

Mite allergen test Fall

Continuous air monitoring

Indoor and outdoor monitoring

four seasons

Personal exposure monitoring*

four seasons

*a part of subjects

Data analysis will be performed before March, 2011.

Schematic outline of the study

Health Effect AssessmentQuestionnaire

Blood sampling

Factors related to asthmaMite allergen test

Questionnaire

Exposure Assessment

Evaluation of the association between exposure to traffic-related air pollutants and the onset of asthma among children

Air pollution monitoring of EC and NOxMeasurements of personal exposure to NOx

Verification

The long-term average exposure of air pollutants (EC and NOx) is estimated by simulation model at the residence and the school.

Provisional results of continuous air monitoring

BC concentrations in March, 2006

0

1

2

3

4

5

6

0ｍ 20ｍ 50ｍ 100ｍ distant place

Distance from the roadside

BC

（μ

g/m

3 )

NOx concentrations in March, 2006

0.00

0.02

0.04

0.06

0.08

0.10

0.12

0ｍ 20ｍ 50ｍ 100ｍ distant place

Distance from the roadside

NO

x（p

pm

)

The concentrations of PM2.5, black carbon (BC), and NOx have been continuously measured at 4 sites (0m, 20m, 50m, 100m) near each of 10 major roads and 7 sites distant from major roads.

Conclusions Various efforts during the past several decades

have improved industrial air pollution. The problems of traffic-related air pollution have

been rising in response to the increase of automobiles.

Some studies suggest the health effects of traffic-related air pollution. However, the relationship between the incidence of asthma and traffic-related exposures should be further evaluated.

Further studies are also needed to clarify the health effects of fine particles in relation to automobile traffic.

Thank you very much for your attention.

(Outlook from Mt. Rokko, Hyogo)

谢 谢！