Archive for November, 2018


Wednesday, November 7th, 2018

Air pollutin is a global emerging problem.

It affects all age groups but more affected age groups are children and elderly.

Bad air quality is known to exacerbate asthma in children and adults,and COPD in adults.

Now ,there is growing evidence that ,bad air quality may cause asthma in children and adults.

Particulate matters(PM) suspended in air may be inhaled and if the size is 2.5 micron or less(PM2.5),it may reach to the lower respiratory tract easily.

It may irritate the airways and cause asthma exacerbation.

If the airway is repeatedly irritated,it may become hyperreactive.

Other dangerous agent is ozone which adversly affects respiratory tract.

According to a study published in American Journal of Respiratory and Critical care medicine, people from areas of bad air quality depending on high ozone and PM2.5 level had high numbers of visits to the respiratory emergency department in comparision to the people from high air quality.

Data were analysed from 38.4 million visits to the department of respiratory emergency from 869 countries..Data represented 45% of US population including children,adults(18-65 years of age) and elderly beyond 65 years of age.Daily rates of respiratory emergency visits were 1.20 for all ages,1.90 for children,0.94 for adults and 1.37 for elderly over 65 years of age per 10000 population.The maximum 8 hour ozone per day varied from 8ppb to 34 ppb with a mean interquartile range of 16.54ppb.The level of PM2.5 ranged from 1.9mcg/m3 to 9.8mcg/m3 per day with an average of 5.3 mcg/m3. There was a positive association between respiratory emergency visits and ozone level.The rates of emergency visits were higher in children.

The study shows a causal relationship is likely between respiratory ailments and level of ozone and PM2.5 in ambient air



Strosnider H, Chang H, Darrow L, Liu Y, Vaidyanathan A, Strickland MJ. . Age-specific associations of ozone and PM2.5 with respiratory emergency department visits in the US [published October 2, 2018]. Am J Respir Crit Med. doi:10.1164/rccm.201806-1147OC