For most people, summer is the time to get outdoors -- to work in the garden, play ball or take a walk. But all too often, the sultry season makes Melvin Ridge a prisoner inside his home in Northeast Baltimore.
"I can tell as soon as I open a window or step out the door when the air's not clean," he said last week. "I have to get back into an air-conditioned room or car to get away from it."
Mr. Ridge, a retired truck driver, has chronic emphysema. He needs repeated whiffs of oxygen and a medicine chest full of drugs to help him breathe.
But even that is not enough when the air is polluted, he says.
Summer is smog season in Maryland. For most people, if they even notice, that may mean little more than tightness in the chest, a scratchy throat and maybe some wheezing if they exert themselves on a blistering afternoon. Some have wondered whether the government is making too much fuss over smog, especially because the state plans to fight it by making Baltimore and Washington area motorists wait longer and pay more to pass the never-popular auto emissions tests.
The air is visibly clearer, critics say, and they grumble about having to pay up to $450 in repairs if their cars and trucks flunk the biennial pollution checks. But for Melvin Ridge and those with asthma, allergies and other lung problems, every penny spent on cleaner air is worth it as they struggle for breath.
About 600,000 Marylanders have lung disease, the American Lung Association estimates.
While smog may not be life-threatening for most people, there is growing evidence it can shorten the breath and inflame the lungs of healthy adults and children playing or working outdoors. It also appears to cause problems at levels far below the safety threshold set by the federal government, which means the public is inhaling harmful pollutants more often and for longer periods -- than the government lets on.
The U.S. Environmental Protection Agency (EPA), faced with a lawsuit over whether its air-quality standard protects the public, is expected to announce its decision tomorrow on whether to change it.
Officially, Maryland's air has been remarkably smog-free so far this summer. There have only been three days when ozone -- the chief ingredient in smog -- reached unhealthful levels (as defined by the federal government) at one of 15 air-sampling stations around the state.
Ozone barely exceeded the federal air-quality limit of 0.12 parts per million for an hour May 22 in Edgewood and July 10 in Aldino, both in Harford County. It climbed above the federal standard for three hours May 23 in Charles County.
With so few violations of the federal ozone standard, it might seem like overkill to impose major new pollution controls now.
But driven by federal law, that is just what Maryland and most of the rest of the nation are doing.
The state unveiled plans recently to beef up biennial emission tests and expand them to 1.5 million cars and trucks in the Baltimore and Washington areas.
It also has drafted rules requiring 1,500 employers in the Baltimore region to get more of their workers to car pool or take public transit to work.
The federal Clean Air Act requires those measures and a lot more to curb smog, state officials say. But some are skeptical.
"There are going to be a lot of very unhappy motorists," Del. Ellen R. Sauerbrey, a Baltimore County Republican, predicted at a hearing in Annapolis last week on the inspection program.
Del. Anthony M. DiPietro Jr., a Baltimore Democrat, warned that "people will leave the state" to avoid the rising costs of auto pollution controls.
But Gilmore Smith, a retired science teacher in Timonium, declared that he and his wife, Katherine, will leave Maryland in the next few years if the state's air doesn't get cleaner.
Mr. Smith has chronic sinusitis, allergies and occasional asthmatic attacks, which he believes are aggravated by pollution.
"To have asthma to start with is like breathing dust," he explained. "As a function of pollutants in the air, which we see and smell sometimes, I'm totally congested, my eyes smart, and I get frontal headaches."
Asthma and allergies are triggered by factors other than air pollution, including exercise, pollen, dust and temperature.
While inhaling ozone-laden air alone does not bring on breathing problems, recent studies indicate it can make people with chronic lung disease more vulnerable and can worsen their symptoms.
Maryland's air has gotten cleaner in the past 20 years, but smog has hung on despite efforts to banish it.
The Baltimore area has the nation's sixth worst ground-level ozone and the Washington area, the 10th worst, according to the EPA.
The main reason the air seems better this year is the weather, say officials.
Cloudless, windless days when temperatures climb above 90 degrees Fahrenheit are needed to "cook" ozone from the mix of hydrocarbons and nitrogen oxides being spewed into the air daily by cars, power plants and other sources.
This May and June, the beginning of smog season, were cooler than normal, according to Fred Davis of the National Weather Service.
July, normally the peak month for smog, has been a little hotter than usual.
But it also has been much rainier, meaning there have been lots of clouds and wind to keep ozone levels down.
"The problem with weather is we have no control over it," said Susan Wierman, acting chief of air pollution controls for the Maryland Department of the Environment. "We could easily wind up back with the situation we had in the summer of 1988, when we had 36 [bad] ozone days, which is easily one-third of the summer."
Pollution controls imposed so far have reduced smog-forming emissions, officials say, but they warn that those gains will be wiped out in the next decade as Marylanders drive more.
State motorists travel 100 million miles per day now, and that figure is expected to grow 3.5 percent a year.
There is little agreement on what it's worth to clean up smog. One economic study put the benefits of healthier air at $1 billion, far below the $15 billion a year that the EPA estimates it will cost cities to curb their pollution.
But the American Lung Association estimates that air pollution costs the nation about $50 billion a year in lost productivity, increased health expenses and premature deaths.
Dr. Sandra Walden knows about the toll pollution takes. She is a Baltimore pulmonary specialist who treats Mr. Ridge and other people with lung disease.
Dr. Walden said she hears from them more often in the summer.
"They call and say, 'I'm short of breath, I'm coughing, my medications don't work,' " she said. "You can gauge what's in the air by how they cough. They're as good a barometer as the air quality index."
A study published this year by the Environmental and Occupational Health Sciences Institute at Rutgers University found that the number of people visiting New Jersey emergency rooms with asthmatic attacks rose and fell with the state's summertime ozone levels, which are similar to Maryland's.
"There's no question we're dealing with a public health threat," said Dr. Bernard Goldstein, a physician and director of the institute.
While ozone may be life-threatening for people whose breathing already is impaired, it also can cause problems for healthy adults and children who work or play outside.
Laboratory tests, in which human subjects inhale measured doses of ozone, show that some people, perhaps 10 percent to 20 percent, lose some of their breathing capacity. Studies also have found that ozone can inflame their airways.
But people may not notice the symptoms or recognize that smog the cause.
"A lot of the effects are fairly subtle, but they probably involve huge segments of the population," said Dr. Robert Frank, professor of environmental health sciences at the Johns Hopkins School of Hygiene and Public Health.
Indeed, nearly 90 percent of Marylanders live in areas where ozone exceeds the federal standard at least once a year.
To get relief, people can simply go indoors, and the wheezing and lung inflammation go away within a day or two.
But no one knows yet how ozone may affect human health after years of repeated exposure.
"Early signs are that there is an accelerated aging of the lungs," said Dr. Rebecca Bascom, a pulmonary specialist at the University of Maryland.
That could be particularly troubling for children, who spend more time outdoors in summer than adults do and generally exercise more.
Studies of children in summer camps in Pennsylvania and New (( Jersey have found that inhaling ozone-laden air diminished their breathing.
"If we wait to find out it'll be too late," warned Dr. Gail Weinmann, a pulmonary specialist at Hopkins who has been studying ozone's health effects. "If we waited until we know whether it causes chronic disease, we wouldn't be able to change anything."
There also are studies showing that ozone can cause breathing problems for at least some people at concentrations in the air as low as 0.08 parts per million -- well below the federal air-quality standard of 0.12 parts per million.
That means that people outdoors are breathing potentially harmful levels of ozone on many more days and for longer periods of time than the official record of "bad" ozone days would indicate.
While ozone in Maryland has exceeded the federal limit on only three days so far this summer, it has been above 0.08 parts per million on 45 days since May 1, according to state figures.
A coalition of northeastern states, environmental groups and the lung association filed a lawsuit challenging the EPA's ozone air-quality standard. The agency agreed to review it, but is not expected to lower it.
Smog-plagued urban areas have been unable to meet the standard after more than two decades, and a stricter limit would only magnify the chore.
Meanwhile, Mr. Ridge stays indoors when the mercury -- and the ozone -- creep up. One hot day this summer when he ventured to the store, he needed help just getting back to his car, he said.
"We don't go anywhere," he said. "We can't go anywhere."