Daily Walking May Worsen Cough in COPD When Black Carbon Is High

TUESDAY, June 23, 2026 (HealthDay News) — For people with chronic obstructive pulmonary disease (COPD), daily walking may worsen cough and expectoration when black carbon (BC) concentrations are high, according to a study published online May 18 in Thorax.

Alícia Josa-Culleré, Ph.D., from the Barcelona Institute for Global Health in Spain, and colleagues conducted a multicenter panel study involving 105 people with COPD during two seven-day periods to examine the combined effect of walking activity and air pollution on daily respiratory symptoms. Daily walking activity was measured using activity monitors, and daily air pollutant concentration was estimated by combining geolocation data with land use regression models. Every evening, dyspnea, cough, expectoration, and wheezing were recorded.

The researchers found an association for walking duration with higher levels of cough and expectoration. All pollutants were associated with higher cough; associations were also seen for BC with higher expectoration, dyspnea, and wheezing. Longer walking duration was associated with higher cough and expectoration only on days with high BC concentrations after including an interaction term. No significant interaction was seen between walking duration and fine particulate matter or nitrogen dioxide. Similar results were seen for step count.

“Our findings support the recommendation to walk for people with COPD, provided that busy roads are avoided where black carbon concentrations are high,” coauthor Judith Garcia-Aymerich, Ph.D., from the Barcelona Institute for Global Health, said in a statement. “It is important to provide accessible spaces for safe walking, as well as to reduce black carbon emissions, a “super pollutant” that is harmful both to respiratory health and the climate.”

Abstract/Full Text