Hot and humid — with unhealthy air — for rest of week

State environmental officials are forecasting unhealthy air quality for “sensitive groups” in parts of the state from Thursday, May 30 to Saturday, June 1, due to predicted elevated concentrations of ground-level ozone pollution.

Southern sections of Middlesex and New London counties will experience unhealthy air quality for “sensitive groups” on Thursday, and this is expected to expand to include Fairfield, New Haven, Hartford and Tolland counties on Friday and Saturday.

Temperatures should be in the high 80s — and perhaps hit 90 degrees — in Connecticut during the next three days, according to some weather forecasts.

What the “unhealthy” forecast means

A forecast of “unhealthy for sensitive groups” indicates increased likelihood of respiratory symptoms and breathing discomfort in active children and adults with respiratory disease, such as asthma, according to a state Department of Energy and Environmental Protection (DEEP) press release.

“Elevated levels of ozone in the air we breathe impact the health of everyone, but sensitive people, including children, the elderly and those with respiratory disease, are at greater risk,” said DEEP Commissioner Daniel C. Esty. “Over the next few days, I urge everyone to take appropriate precautions and consider limiting outdoor exertion during the warmest part of the day.”

How the air gets unhealthy

Ground level or “bad” ozone is created when two types of air pollutants — nitrogen oxides (NOx) and volatile organic compounds (VOC) — react in the presence of sunlight and warm temperatures.

These air pollutants are generated both inside and outside of Connecticut from industrial facilities and electric utilities, motor vehicle exhaust, and gasoline vapors.

The health effects

Unhealthy concentrations of ground level ozone can cause or make worse a variety of respiratory and other health problems, including breathing difficulty, coughing and throat irritation.

Breathing ozone can affect lung function and worsen asthma episodes. Anyone can be affected by ozone and particularly sensitive groups include children and adults who are active outdoors, and people with respiratory disease, such as asthma.

Sensitive people who experience effects at lower ozone concentrations are likely to experience more serious effects at higher concentrations. Especially sensitive individuals should consider remaining in an air-conditioned environment.

What you can do to help

Connecticut experienced 27 unhealthy air quality days during 2012. When air pollution levels are predicted to be “unhealthy for sensitive groups,” DEEP officials recommend:

— Conserving electricity by setting air conditioners to 78.

— “Wait ‘til 8” to use energy intensive appliances like washing machines, dryers and dishwashers.

— Driving less by carpooling, van-pooling or using public transit.

— Telecommuting if possible.

— Refueling your vehicle after dusk and never idling a vehicle unnecessarily.