Health effects of haze

The PM2.5 particles in haze are small enough to travel deep into the lungs and cross into the bloodstream. Here is what that does, who is most at risk, and what actually helps.

Who is most at risk

These groups can be affected at exposures a healthy adult would not notice.

• Children
• The elderly
• People with respiratory conditions — asthma, bronchitis, chronic obstructive pulmonary disease (COPD)
• People with heart conditions such as coronary artery disease
• Smokers

Short-term effects

• Difficulty breathing, chest tightness, chest pain
• Irritated or dry throat, sore throat, cough with phlegm
• Runny or blocked nose, frequent sneezing
• Upper respiratory tract infection
• Irritated eyes, excessive tearing, conjunctivitis
• Skin irritation
• Headache, dizziness, fatigue

These are usually mild and settle once exposure drops.

Long-term effects

• Raises the risk of death from cardiovascular disease and lowers life expectancy
• May contribute to the development of diabetes
• Associated with spontaneous miscarriage, low birth weight, congenital abnormalities and infant mortality

What actually helps

• Cut outdoor activity, especially strenuous exercise.
• Wear a mask outdoors. Surgical and cloth masks do not filter PM2.5 — only a well-fitted N95 does.
• Close windows and doors when the haze is heavy.
• Use the recirculate setting on air conditioning, including in the car.
• Run an air purifier indoors if you can.
• Do not smoke — it adds pollutants to the air indoors.
• Drink plenty of water, at least eight glasses a day.
• Wash your hands and face after being outside, and shower often.