Tropical outlook, NE flooding, and more on air pollution progress and challenges

The flooding in the Northeastern U.S. is easing today, with most of the rivers in flood stage expected to drop below flood stage by Thursday afternoon. No new rain is expected across the region today or Thursday, but some light to moderate rains Friday may slow the recovery efforts. A series of modest rain systems should then cross through the region into early next week. By mid-week, the jet stream is forecast to move poleward and being a more summerlike pattern to North America.

Tropical outlook for the next week
With the coming of a more summerlike pattern next week, we will need to start watching the Western Caribbean for some possible tropical development; wind shear values there are starting to fall to levels where tropical development is possible again. Wind shear is quite low (5-10 knots) over the waters just north of Panama today and will stay low the next few days, but at present the clouds there are sparse and disorganized, and I am not expecting anything to develop this week. Next week things may be more favorable, when the remains of a cold front that pushes off the coast could provide enough of an initial disurbance to kick something off--if the front can push far enough south, where wind shear is lower. Again, I am not really expecting anything to develop, wind shear should still be high enough to make tropical development marginal.

Air pollution progress and health effects
Let's continue our dicussion of air pollution this week, focusing on the health effects. Significant progress has been made in recent years in cleaning the nation's air. Between 1970 and 2004, total emissions of the six major air pollutants regulated by the Environmental Protection Agency (EPA) dropped by 54 percent. This is particularly impressive when noting that the gross domestic product increased 187 percent, energy consumption increased 47 percent, and U.S. population grew by 40 percent during the same time--proof that economic growth and environmental protection do go hand in hand. However, air pollution remains a serious threat to public health and the environment. Outdoor air pollution in the U.S. due to particulate pollution alone was estimated by the EPA in 1997 to cause at least 20,000 premature deaths each year. Other estimates place this number at 50,000 to 100,000 deaths per year. A study in Southern California found that living near major roadways increases the risk of childhood asthma. Among those long-term kids studied that had no parental history of asthma who lived within 75 meters of a major road, 59% of asthma was attributable to residential proximity to the road. The annual costs of air pollution per person in the Los Angeles area were estimated at $3000-$4000 per person back in the 1970s. This cost has dropped significantly, and is now estimated at about $1000 per person. This $1000 per person amounts to $3 billion per year just for the Los Angeles area, and further efforts to control air pollution need to be looked at to see if this cost--and the human suffering that accompanies it--can be further reduced. Of course, the costs to businesses will also have to be factored in--for example, emissions control equipment can add over $1000 to the cost of a vehicle.

How to protect yourself when air pollution is high
You're exposed to air contamination any time you breathe polluted air. But when you exercise, work in the yard, or do other strenuous activities that make you breathe harder and faster, you take more polluted air into your lungs. Exposure to ozone and particle pollution is linked with a number of significant health problems. Children, people with lung disease, older adults and people with heart disease tend to be more vulnerable.

You can help protect yourself simply by changing the time or intensity of your exercise, yard work or other strenuous activities. Use the Air Quality Index (AQI) and daily air quality forecasts to help you determine when you need to make changes. These are posted on the Weather Underground web site for most major cities in the U.S., or you can get them from www.airnow.gov.

The AQI is a color-coded scale that tells you who needs to take steps to reduce their exposure to ozone or particle pollution and when. If you have heart disease, for example, pay close attention when particle pollution reaches Code Orange levels. If you have asthma, youll want to pay attention at Code Orange for particle pollution and for ozone.

Ozone pollution tends to be more of a problem in the warm summer months. Levels of this colorless, odorless gas can increase during the day, peaking in the late afternoon to early evening. At elevated levels, ozone is a threat to everyones health, but those who are most susceptible are people with lung diseases such as asthma, children, older adults and healthy people who are active outdoors.

Ozone causes cells in the lungs to swell and get inflamed similar to what happens to your skin cells when you get sunburned. Repeated episodes of this kind of inflammation may cause permanent damage to the lungs. Ozone aggravates asthma and other lung diseases, leading to increased medication use, visits to doctors and emergency rooms, and hospital admissions. Recent studies have also linked ozone exposure with premature death.

Can you tell if ozone is affecting you? You may experience symptoms like coughing, a burning sensation when you breathe, chest tightness, or shortness of breath. If you have asthma, you may find yourself needing to use medicine more frequently, or you may have asthma attacks requiring a doctor's attention.

Particle pollution can occur at any time of year. If you live in an area with high woodstove use, for example, particle pollution may be higher in your community in winter. In many areas of the eastern U.S., particle pollution may also be high in the summertime, often accompanied by high levels of ozone. People with heart or lung disease, older adults, and children are considered at greater risk from particle pollution than other people, especially when they are physically active.

Particle pollution can aggravate lung disease, causing asthma attacks and acute bronchitis, and may also increase susceptibility to respiratory infections. Particle pollution has been linked to heart attacks and arrhythmias in people with heart disease, and also to premature death in people with heart or lung disease.

If you or your children are healthy, you're not likely to suffer serious effects from short-term, peak exposures to particle pollution. But when particle pollution is elevated, you may experience irritation of the eyes, nose and throat, coughing, chest tightness, and shortness of breath.

Reducing your exposure to ozone and particle pollution isn't hard. Just take it a little easier. If pollution is forecast to be high in your area, cut back or change the time of your strenuous activities: go for a for a walk instead of a jog, or reschedule for times when the air quality is expected to be better. If you have asthma, be sure to follow your asthma action plan with air pollution levels are high. And don't exercise near busy roads; particle levels generally are higher in these areas.

Particle levels can be elevated indoors too, especially when outdoor particle levels are high, such as during an inversion or when there's a lot of smoke outside (such as from a wildfire). Certain filters and room air cleaners can help reduce indoor particle levels. You can also reduce particle levels indoors by not smoking inside or vacuuming, and by reducing your use of other particle sources such as candles, wood-burning stoves, and fireplaces. Go to http://www.epa.gov/iaq/homes/index.html for more information.

My next blog will be Thursday.
Jeff Masters