The official start is just eight days away. The American College of Allergy, Asthma and Immunology says there is no way to accurately predict pollen counts or how bad the spring allergy season will be.

But some experts think we may be facing a "pollen superburst" this year. Pollen usually happens in a sequence. Trees first, then flowers and weeds. Cold weather slowed things this year, but with recent warm-ups, trees and flowers could start pollinating all at once.

The air we now breathe has about 350 parts of carbon dioxide per million parts of air. Experts expect carbon dioxide levels to double within the next three to six decades, so the researchers studied ragweed growth at both 350 parts and 700 parts carbon dioxide per million parts of air.

They also released the ragweed seeds at different times to simulate early and late growing seasons.

A longer growing season was associated with an increase in pollen production for seeds grown at atmospheric carbon dioxide levels that were similar to current conditions. But it seemed to have less impact when seeds were exposed to the highest carbon dioxide levels.

"In future climates with elevated [carbon dioxide], we predict pollen production will be just as robust in years with late springs as in years with early springs," the researchers wrote. "Overall, pollen production in ragweed can be expected to increase significantly under predicted future climate conditions."

The study was conducted by researchers from Harvard School of Public Health's Exposure, Epidemiology, and Risk Program, and Harvard Medical School's Center for Health and the Global Environment. It was funded through a grant from the National Oceanic and Atmospheric Administration.

Experts say Americans are in for a pollen "superburst" that could wallop much of the country in the next couple of weeks and spell misery for an estimated 40 million allergy sufferers.

Roger Emert, an allergy specialist at the New York Presbyterian Weill Cornell Medical Center, shared his tips for combating watery eyes and the sniffles on "Good Morning America."

Parents of food-allergic children must be diligent in checking their kids' loot before giving them access to it. Instruct children not to eat anything until they get home. Then read labels carefully, looking for allergens. Be aware that the ingredient Mandalona is a nut substitute derived from peanut meal.

Make sure your kids have a good meal before they go out trick-or-treating, the Food Allergy and Anaphylaxis Network recommends, so they're not hungry.

Talk with neighbours in advance about having safe treats for your kids; consider supplying them. Some companies, including Nestle and Mars, for instance, produce peanut-free candy bars. Consider such non-food treats for trick-or-treaters as colouring books or pens and pencils.

If your child is old enough to go out without an adult, have him go with at least two buddies who know about his food allergies. Make sure he carries his medicine. Epinephrine, used to treat severe allergic reactions, is most effective when used as soon as possible after a severe allergic reaction. It is available by prescription, most commonly as the Epi-Pen auto-injector.

Denise Bunning of Chicago has two children with severe food allergies. Her son Bryan was rushed to the hospital one year after eating a single gummy worm, reported WMAQ-TV in Chicago.

"The bulk container had previously contained a chocolate nut, so just the residue on the gummy worm was enough to cause my child to have an anaphylactic reaction," Bunning said.

Experts say eight foods are the most common food-allergy culprits: milk, eggs, peanuts, tree nuts, fish, shellfish, soy and wheat.

Parents of food-allergic children must read every candy label in their child's Halloween bag to ensure their child's safety.

Ironically, because we have been so successful in eliminating disease and parasites in Western Europe and North America our immune systems, which evolved in very dirty environments under constant assault from a multitude of diseases and parasites, goes awry absent these external modulators, and attack our own tissues.

Hookworm, as a foreign protein in contact with our tissues, has to suppress or modulate our immune response or it will be attacked and destroyed by our immune system. Think of that time you got a piece of hamburger stuck in a gum and did not have access to dental floss for the better part of a day. Remember the inflammation?

So, hookworm and these other parasites are down-modulating some aspect of our immune system, the result is no asthma, hayfever and Inflammatory Bowel Disease in individuals with sufficient numbers of hookworm. In effect, hookworm infestation suppress hay fever, asthma, colitis, Crohn's disease and Inflammatory Bowel Disease (IBD).

Really it isn't a cure since the effect only lasts as long as the infestation. Eliminate the worms and your asthma or Inflammatory Bowel Disease will return.

They suggest adults should use older non-prescription antihistamines and decongestants to stop the flow of mucus that causes the cough.

Children can be harmed by cough medicines, they warn, and they will usually get better without help.

It is possible children could be over-sedated with the medication, they said.

A productive cough produces phlegm or mucus (sputum). The mucus may have drained down the back of the throat from the nose or sinuses (postnasal drainage) or may have come up from the lungs. A productive cough generally should not be suppressed; it clears mucus from the lungs.

A nonproductive cough is dry and does not produce sputum. A dry, hacking cough may develop toward the end of a cold or after exposure to an irritant, such as dust or smoke.

"The eight major food allergens account for 90 percent of all documented food allergic reactions, and some reactions may be severe or life-threatening," said Robert E. Brackett, PhD, Director of FDA's Center for Food Safety and Applied Nutrition. "Consumers will benefit from improved food labels for products that contain food allergens."

A 1999 FDA study in Minnesota and Wisconsin found a quarter of the baked goods, ice cream and candy its scientists sampled failed to list peanuts or eggs as ingredients.

Food labels must now list the common name of the product as well as the name of the specific allergen it contains. A product containing a protein derived from milk called casein, for example, must list both "milk" and "casein" on its label. Labels also must specify the type of fish, crustacean or tree nut the product contains.

Parents might also consider sending their children out with some fruits or nuts as snacks.

"Discuss with children what constitutes a reasonable number of treats to consume when they get home and be cautious with homemade treats -- if you are unclear about the source of the treat, throw it away," Elisabetta Politi, nutrition manager at the Duke Diet and Fitness Center, said in a prepared statement.

Falls are among the most common Halloween-related injuries, noted Claudia McCormick, program director of the Duke Trauma Center. Parents need to make sure that costumes won't cause children to trip. Children should wear well-fitting shoes. Don't send them out in floppy shoes or shoes with high heels. And they should walk in well-lit areas.

Persistent and potentially dangerous mold is a problem mostly in New Orleans, where buildings spent days and in many cases weeks under water. That's more than enough time for moisture to permeate walls and floors and provide an ideal growth medium for mold.

Health and environmental officials Wednesday urged residents returning to flood-affected areas to quickly clean up mold contamination to avoid potential illnesses. Small amounts of mold can be cleaned by homeowners themselves. Moldy surfaces over 10 square feet require professional removal, said Steven Redd, MD, chief of the CDC's Air Pollution and Respiratory Health Branch.

"Those [surfaces] that can't be cleaned need to be removed," Redd told reporters.

The researchers looked for genetic variations known as polymorphisms on two genes known to be associated with asthma and allergies, IL-4RA and IL-13.

People with polymorphisms on those genes were more likely to have asthma and allergies and less likely to have a glioblastoma.

"For example, we found that one genetic variant that causes a two-fold risk in asthma susceptibility reduces the risk of glioblastoma multiforme by 40 percent," said Schwartzbaum.

Why genes that promote asthma or allergies might offer protection against brain tumors is unclear, said Schwartzbaum.

She speculated that the gene variations might hinder inflammation in the brain, even though those same genes help cause inflammation in the lungs.

The Environmental Protection Agency has found that fewer than 30 percent of people with asthma are taking simple steps to reduce exposure to those triggers. Secondhand smoke, cockroaches, dust mites, mold and ozone can cause asthma in young children or set off asthma attacks.

Experts believe that by helping patients manage their asthma more effectively and keeping them out of the ER, they could save the health care system more than $500 million each year. The ultimate goal: Cutting asthma-related hospitalizations by 50,000 over the next five years.