- Chronic obstructive pulmonary disease (COPD)
affects nearly 15 million people in the United States, and is the third main
cause of mortality.
- Outdoor air pollution
levels have been linked to increased respiratory symptoms in COPD and
studies have indicated that high indoor temperatures and pollution levels can
also cause COPD exacerbation.
- Keeping indoor heat
and pollution to optimal levels has the potential to improve disease outcome.
Increased indoor temperatures and
pollution levels are associated with exacerbation of COPD
according to a recently conducted study by researchers at the Johns Hopkins
For The Study
Though outdoor pollution
is known to exacerbate COPD symptoms, there
is very little research and evidence
available on the effect of the quality of indoor air in COPD patients,
especially in developed countries
‘Modifying indoor climate to optimal levels reduces respiratory symptoms in chronic obstructive pulmonary disease (COPD).’
research is needed to understand the factors that cause indoor pollution and
exacerbation of COPD, and ways to address them
of The Study
McCormack, MD, MHS, and her colleagues at the Johns Hopkins University
longitudinal study on 69 volunteers suffering from moderate to severe COPD,
during some of the hottest days of the year.
"Previous studies have found that the elderly
are particularly vulnerable to the effect of heat and more likely to die or be
hospitalized during heat waves," said Dr. McCormack, an associate professor of
medicine at Johns Hopkins and lead study author. " To our knowledge, this is the first study to report an interactive
effect between indoor temperature and indoor air pollution in COPD
The volunteers were asked to complete a daily questionnaire that included the Breathlessness,
Cough, and Sputum Scale (BCSS), which contained a standardized rating of
respiratory symptoms. In addition, their lung function was assessed by
performing a daily spirometry. The frequency of using rescue inhalers to
control their symptoms was recorded by the patients.
data was analyzed, and two air pollutants in their homes namely fine
particulate matter (PM2.5
) and nitrogen dioxide (NO2
were measured along with outdoor temperatures during the study period.
Results of The Study
investigators reported the following findings
Takeaway From The Study
- Participants of the
study spent most of their time indoors. On the days they ventured out, it was
for around two hours on an average.
scores worsened with higher indoor temperatures and so did the use of rescue
inhalers by the participants.
- The effect of increasing
indoor temperatures was additionally magnified by high levels of indoor
pollutants, namely PM2.5 and NO2. A 10 degree rise in
temperature within the home at the 75th percentile of PM2.5 levels
led to a severe increase in symptoms, as compared to only a mild aggravation of
symptoms that occurred when the levels of PM2.5 were at the 25th
percentile inside the home.
- Worsening of symptoms occurred
immediately on exposure to higher indoor temperatures, and lasted for a couple
function, which was assessed by spirometry, remained unaffected by
rising indoor temperatures or increasing levels of indoor air pollutants.
of 86 percent of the participants living in residences with some form of air
conditioning, it was not turned on for 37 percent of the study days.
was an aggravation of respiratory symptoms on the days the participants spent
outside, notwithstanding the fact that it was for a brief period only.
- Most elderly persons
and those suffering from COPD spend the major part of their day indoors.
Considering the fact, the findings of the study assume all the more importance.
"Given that participants spent an overwhelming majority of their time indoors,
which we believe is representative of patients with COPD generally, optimizing
indoor climate and reducing indoor pollution represents a potential avenue for
improving health outcomes," Dr. McCormack said.
findings of the study present an opportunity for doctors and healthcare
professionals to try targeted interventions. Also, policy and law makers need
to take note of the findings and draw up strategies to minimize and protect the
vulnerable population from the adverse effects of the climatic conditions.
In conclusion, it may be added that indoor air pollution, which exacerbates COPD symptoms, is a
highly modifiable parameter
. Such modifications would mean a
cost-effective and novel therapeutic approach for a disease that has only
limited treatment options.
- The Effects of Air Pollution and Temperature on
COPD - (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4878829/)