This study examined the effects of air pollution on infant and child respiratory mortality in four large Latin American cities: Mexico City, Santiago, Chile, Sao Paulo, and Rio de Janeiro, Brazil. Daily counts of respiratory deaths among infants and children were analyzed in relation to particulate matter (PM10) and ozone (O3) levels using statistical models. The results found small increases in risk of respiratory mortality among infants and children associated with higher PM10 and O3 levels, with the strongest effects seen for lower respiratory infections among infants. The study adds to evidence that air pollution exposure can negatively impact children's respiratory health.

1. Effects of Air Pollution on Infant and
Children Respiratory Mortality in
Four Large Latin-American Cities
Journal of Environmental Pollution
Nelson Gouveia and Washington Leite Jungerb
Received in revised form, 24 August 2017,Accepted 25 August 2017

2. INTRODUCTION
• Air pollution has become an important public health concern
for most cities in the world.
• Exposure to ambient levels of air pollution can have several
health impacts in adults and elderly to impacts in early life
and during pregnancy.
• Infants and children are more susceptible population to the
health effects of air pollution.
• The consequences of early life exposure include
o impairment of lung function
o increased risk of respiratory illness
o higher probability of premature mortality

3. INTRODUCTION
• However, there are relatively few studies that have examined
the effect of air pollution on mortality during childhood,
• Latin America :
o has a very large children population
o is highly urbanized
o urban levels of air pollution are amongst the higher in the world
• In this paper the effect of air pollution on infant and children
mortality in four large urban centers in Latin America: Mexico
City in Mexico, Santiago, Chile, Sao Paulo and Rio de Janeiro
in Brazil.

4. METHODS
• Daily counts of deaths due to respiratory diseases in infants
(<1 year old) and children 1-5 years old, and of lower
respiratory infections (LRI) in infants and children 1-14 years
old with daily levels of PM10 and O3 in the four cities.
• Daily 8-hr maximum moving average for O3 and daily 24-hr
mean average of PM10 were calculated averaging
measurements from all monitoring stations in each city.
• Daily mean values of temperature and humidity using natural
splines initially with 3 or 6 0F each at lags 0, 1, 2, and 3, and
then using moving averages was also observed in analysis.

5. METHODS
• City-specific analysis using Generalized Additive Models
(GAM) in Poisson regression to fit the time-series data,
according to the equation:
• After building a core model for each city, air pollution levels
were introduced in lags of up to three days (single lag
models-SLM) and also examining the cumulative effect using
constrained polynomial distributed lag models (DLM).
• The analyses were carried out per cause of death for each
age-group.

6. METHODS
• Risk estimates were calculated by introducing the air
pollution variables into the models as linear terms presenting
them as percentage relative risks for each increment of 10
mg/m3 at PM10 or O3 levels assuming a significance level of
5%.
• Because of the different geographical position of each city,
“warm season” and “cold season” were defined in different
ways, with warm season spanning from October to March
and cold season from April to September.
• All analyses were conducted using the software R version
2.15.1

7. RESULTS
• Despite these being the largest, the daily number of infants
and children deaths by respiratory diseases was low,
especially when examining the lower respiratory infections
(LRI) subgroup.
• Mexico City presented the highest mean count for respiratory
infant mortality (1.8 deaths/day) and Santiago the lowest
(0.13 deaths/day).
• Mean levels of PM10in these cities varied from 46.7mg/m3 in
Sao Paulo to 78.4mg/m3 in Santiago, while for O3 values
ranged from 28.1mg/m3 in Rio to 138.6mg/m3 in Mexico City.

8. RESULTS

9. RESULTS
• Levels of O3 were higher during the warm season for all
cities.
• Levels of PM10 also varied by season being higher during the
colder months
• Mexico City was the driest city and Rio de Janeiro the
warmest while the two other cities presented a more
temperate weather.
• There was no discernible lag pattern of effect either for PM10
or for O3.

10. RESULTS
• For PM10 in Sao Paulo and O3in Santiago they were
negative, indicating a decrease in mortality risk for an
increase in pollution levels.
• Higher effect estimates were observed for Rio de Janeiro
but they also exhibited wider confidence intervals.
• In distributed lag models for PM10 larger effects were
observed for both causes of death in the older age group in
Rio de Janeiro while negative and significant results were
detected for the younger age group in Sao Paulo.
• Fewer significant effect estimates were observed for O3
noting that for Santiago both results in the older age group
were negative.

11. RESULTS
• Fixed and random effects meta-analysis For PM10 show the
percentage increase in risk of death due to respiratory
diseases in under 1 year old in a fixed effect model was
0.47% (0.09-0.85).
• For respiratory deaths in children 1-5 years old the increase
in risk was 0.58% (0.08-1.08) and a higher effect was
observed for LRI 1e14 years old [1.38% (0.91-1.85)].
• For O3, the only summarized effect estimate statistically
significant was for LRI in infants.

12. RESULTS

13. RESULTS

14. RESULTS
• Percentage increase in daily mortality for respiratory disease in children 1-
5 years old for a 10mg/m3raise in PM10and O3 levels in single lag models,
for Rio de Janeiro, Sao Paulo, Santiago and Mexico City, 1997-2005.

15. RESULTS
Percentage increase in daily mortality for acute lower respiratory infections in
infants for a 10 mg/m3 raise in PM10 and O3 levels in single lag models, for Rio
de Janeiro, Sao Paulo, Santiago and Mexico City, 1997-2005.

16. RESULTS
Percentage increase in daily mortality for acute lower respiratory infections in
children 1-14 years old for a 10mg/m3 raise in PM10 and O3 levels in single
lag models, for Rio de Janeiro, Sao Paulo, Santiago and Mexico City, 1997-
2005.

17. DISCUSSION
• Results are consistent with studies carried out previously in
the same cities. In Sao Paulo it was found that CO, SO2 and
PM10 were associated with mortality for respiratory diseases
in children under 5 years old.
• In Mexico City, exposure 3-5 days before death was
associated with increased infant death.
• A later study confirmed this finding specifically for respiratory-
related infant mortality and indicated that infants with lower
SES are at higher risk of mortality when exposed to ambient
PM10 and O3

18. DISCUSSION
• Other studies have also found a relationship between PM
and infant mortality in places with relatively lower pollution
levels, such as the United States and Japan.
• In addition, a meta-analysis of 10 European birth cohorts
found an association between air pollution and pneumonia in
early childhood, one of main specific causes of respiratory
deaths in children.
• The exact mechanisms of how exposure to air pollution
affects the respiratory system are not fully understood, but
likely involve the interplay of environmental and epigenetic
effects .

19. DISCUSSION
• Studies have suggested that oxidative stress and
inflammation are the primary mechanisms by which ambient
air pollution induces adverse health effects.
• Another analysis showed that particulate matter was
associated with small decreases in lung function in school-
children and it is known that impaired lung development
contributes to infant mortality.
• the effect of air pollution on children respiratory health can
initiate even before birth as exposure during pregnancy has
also been linked to decreased lung function in infancy and
childhood

20. DISCUSSION
• Estimating the global impact of air pollution on the children is
important to help design interventions that aim to reduce
population exposure.
• It is also necessary to estimate the economic costs of the
health effects of this exposure.
• As air quality is increasingly highlighted as an important
determinant of population health, cities must strive to ensure
a better quality of air and, consequently, a better quality of life
for its inhabitants.
• It is imperative to take rigorous actions to reduce air pollution
exposure and thus long-term respiratory mortality.

21. THANK YOU