EVA studyEmisiones Vehiculares y Asma

Centers for Disease Control Air Pollution Respiratory Branch

Instituto Nacional de Salud Pública Emory University School of Medicine

Division of Pulmonary and Critical Care Medicine

Background

• In Ciudad Juarez 93% of the truck industry and 61.8% of the buses use diesel fuel

• Outdated vehicular fleet• Vehicular sources: largest contributor to

the emissions inventory• Ciudad Juarez – El Paso is one of the

busiest land ports in the US borders (4th)• Trucks must circulate through the city

before reaching the border

Environmental Health Perspectives. 108(7):A308-15, 2000 Jul.

Question

• What are the health effects associated with traffic related emissions among asthmatic children in Ciudad Juarez?– Health effects associated with traffic related to

the border crossing – Differential health effects in asthmatic and

non-asthmatic children – Is exposure associated with airway

inflammation?– Does atopy (allergic status) modify the risk?

MethodsLongitudinal study of school asthmatic and non-

asthmatic children aged 6 –12 years from low to medium SES

Schools located in close proximity to main roads that contribute traffic flow to border crossings

Asthmatics: Medical diagnosis of asthma with at least two asthma-related ER visits in the last year (from IMSS)

Gender and age matched non-asthmatics: selected from same schools

Study Design

38 Schools

100 asthmatic children

100 healthy children

n = 100 (50 asthmatics and 50 healthy) n = 100 (50 asthmatics and 50 healthy)

Follow-up for 16 weeks Follow-up for 16 weeks

Activities: General questionnaire- Daily record- Medical/hospital visits- Exhaled NO (8 times)- Spirometry (8 times)- Exhaled Breath analysis x1 - Nasal lavage x 1 - Urine for PAH x 1- Skin testing

Ambient data: Local PM2.5 monitoring (48 h average)- Elemental Carbon (Quartz) -Passive samplers for NO2 monitoring (1 week) - Traffic counts-Geocoding of schools and houses-Meteorological data

winter wintersummer

Methods • Analysis

– Mixed effects model, adjusting for age, gender, ETS, day of week, seasonality, school, BMI.

• GIS variables – Road density, average traffic counts, distance to main

roads– Buffers 50m, 100m, 200m, 300m

• Exposure– School-level (air pollutants, GIS variables)– Subject or house-level (GIS variables)

Study population Variables Asthma No asthma p Atopic Non

atopic p

Total 95 99 89* 99

Female 31 41 34 37

Male 64 58 55 62

Age mean (SD) 9.0 (1.75) 9.0 (1.61)

Mean Weight (kg) 37.4 (18-80) 38 (19-87)

Atopy % 58% 37%

Av. FENO 5.6 3.1 <0.01 5.4 3.4 <0.05

Av cough rate 0.108 0.065 <0.01 0.083 0.083 ns

Av. Wheeze 0,021 0.002 <0.01 0.012 0.009 ns

Av. Phlegm 0.090 0.034 <0.01 0.061 0.057 ns

Av. Albuterol 0.083 0 <0.01 0.039 0.033 0.07

Av. Overall symptoms 0.302 0.102 <0.01 0.196 0.183 ns

IDR: avg # of questionnaire positive responses/100 question-entries

Pulmonary function tests

Participants Asthma No asthma

FEV1 (L) 1.68(0.51) 1.77(0.49)

FEV1 % (SD) 89.6 (17) 98.1 (15)

FVC (L) 2.24 (0.70) 2.23(0.63)

FEV1 / FVC (SD) 76 (11) 83 (12)

Asthma Severity

IntermittentMild persistentModerate persistentSevere

13%8% 1%

78%

Traffic and Road Data: Juarez, Mexico

Schools

Houses

Air monitoring

Results

Nitrogen Dioxide Monitoring Schedule

Monitoring Dates

Sch

oo

l ID

(o

rde

red

by

zon

e)

12/1/2002 3/1/2003 6/1/2003 9/1/2003 12/1/2003

19202731333536141518394344461316212332404142

46

22252829374550515253545556

Zone

1111111222222233333333444444445555555

Approx: 3904 Monitoring Days

* Note that monitoring occurs generally in consecutive two-day periods and, therefore, appear in this plot to be two-week averages.

Particulate Matter Monitoring Schedule

Monitoring Dates

Sch

oo

l ID

(o

rde

red

by

zon

e)

12/1/2002 3/1/2003 6/1/2003 9/1/2003 12/1/2003

19

20

27

31

33

36

35

8

14

15

18

39

44

46

13

16

21

23

41

4

6

28

29

37

45

50

51

52

53

54

55Zone

1

1

1

1

1

1

1

2

2

2

2

2

2

2

3

3

3

3

3

4

4

4

4

4

4

5

5

5

5

5

5

Approx: 1807 Monitoring Days

ppb

Levels of pollutants measured at participating schools in Ciudad Juarez, 2002 - 2003

Exposure analysis and health effects

no2.sch

fen

o.lo

g

-2

-1

0

1

2

3

10 15 20

Association of Log-eNO and NO2 at the schools

Association between NO2 at schools and exhaled NO

-0.15

-0.1

-0.05

0

0.05

0.1

0.15

0.2

All data Asthma Asthma andatopy

Asthma noatopy

No asthmaatopy

Atopy

β (± S.E.) : adjusted for age, sex, BMI, ETS, day of wk, and season* : p < 0.05

*

Association of exhaled NO with PM2.5, EC, and NO2 at schools

-0.1

-0.05

0

0.05

0.1

0.15

β (± S.E.) : adjusted for age, sex, BMI, ETS, day of wk, and season* : p < 0.05

PM2.5 EC NO2 PM2.5 EC NO2

Road length exposure (<50m)

• Length of road within 50 meters of a subject’s home was significantly associated with eNO levels in the asthmatics

sl.all.50

fen

o.lo

g

0.10 0.15 0.20 0.25 0.30

-4

-2

0

2

Subject level length of road (all roads) within 50 meters against Log-eNO

sl.all.50

fen

o.lo

g

0.10 0.15 0.20 0.25 0.30

-4

-2

0

2

control

0.10 0.15 0.20 0.25 0.30

case

Subject level roads within 50 meters by asthma/no-asthma statusNo asthma Asthma

sl.all.100

fen

o.lo

g

0.4 0.6 0.8 1.0

-2

-1

0

1

2

3

control

0.4 0.6 0.8 1.0

case

Subject level length of roads in 100 m by asthma/no-asthma statusNo asthma Asthma

-10

-8

-6

-4

-2

0

2

4

6

8

10

All Asthma Asthma andatopy

Asthma noatopy

No asthmaatopy

Atopy

Association between the subject-level 50m buffer and exhaled NO

β (± S.E.) : adjusted for age, sex, BMI, ETS, day of wk and season * : p < 0.05

*

*

Traffic counts and exhaled NO

st.all.200

fen

o.lo

g

0 200 400 600 800 1000

-2

-1

0

1

2

3

control

0 200 400 600 800 1000

case

Traffic counts within the 200m buffer and log-eNO by case/control status

No asthma Asthma

st.all.300

fen

o.lo

g

0 500 1000 1500 2000

-2

-1

0

1

2

3

control

0 500 1000 1500 2000

case

Traffic counts within the 300m buffer and log-eNO by case/control status

No asthma Asthma

st.all.400

fen

o.lo

g

0 1000 2000 3000

-2

-1

0

1

2

3

control

0 1000 2000 3000

case

Traffic counts within the 400m buffer and log-eNO by case/control statusNo asthma Asthma

st.all.500

fen

o.lo

g

0 1000 2000 3000 4000 5000

-2

-1

0

1

2

3

control

0 1000 2000 3000 4000 5000

case

Traffic counts within the 500m buffer and log-eNO by case/control status

No asthma Asthma

Symptoms

• Road length in the 50m buffer had a marginal significant association (p=0.06) with cough episodes in asthmatics, but not in non-asthmatics.

• No significant associations with eNO and/or respiratory symptoms with distance to roads at schools

Conclusions

• In ciudad Juarez, NO2 exposure in schools is associated with increased exhaled NO

• Road-length (density) exposure within a 50 m buffer (home-level) is associated with increased exhaled NO and possibly cough only in asthmatics children

• No significant associations with PM2.5, or EC

• EPA Border 2012– US EPA4 97686501-0

• USC, Department of Preventive Medicine– Mike Jerret – Kiros Berhane

• Zev Ross, Zev Ross Spatial Anlaysis. • Salúd Publica, Cuernavaca

– Isabelle Romieu, Silvia Flores, Marlene Cortez. Rafael Santibañez, Mauricio Hernandez

• CDC, NCEH– Stephen C. Redd, Allison Stock, Larry Needham, Andreas Sjodin,

Mike Mcgeehin • MIT & US Mexico foundation for the Science

– Mario Molina, Luisa Molina• Environmental Defense Fund

– Carlos Rincón• UACJ

– Rafael Granados and GIS lab team