NEW! Canadian Military History Trivia Challenge
Search

Canadian Military History Trivia Challenge

Take the quiz and Win a Trivia Challenge prize pack!

Canadian Military History Trivia Challenge

Take the quiz and Win a Trivia Challenge prize pack!

Health File: Welcome To The Sneezin’ Season

Drippy, itchy, scratchy, wheezy, weepy, sneezy and cranky.

Drippy, itchy, scratchy, wheezy, weepy, sneezy and cranky. 

No, not new names for the fabled Seven Dwarves—a description of symptoms suffered by the nine million or so Canadian seasonal allergy sufferers and three million asthmatics. For them it’s not welcome news that global warming is stretching our warmer seasons. Spring arriving a week earlier and fall leaving several days later just stretches out their misery.

By now, warmer weather has brought on the sneezin’ season across Canada as wind picks up pollen from trees, grass, weeds and mould spores and distributes them, largely, it seems at times, on unwelcoming human hosts. These tiny particles are harmless to most of us, irritants to about a quarter of us, and deadly to a few.

The Allergy/Asthma Information Association website (www.aaia.ca) explains some people’s immune systems mistake harmless pollen, moulds, dust or food (called allergens) for health-threatening invaders. When allergens come into contact with certain immune cells lining the nose, lungs, skin and intestinal tract, the cells release chemicals that cause inflammation and allergy symptoms. The familiar march of symptoms begins: congestion as fluid fills up spaces between cells, itchiness, sneezing, wheezing and difficultly breathing as airways swell and are covered with more and thicker mucous.

The most common means of coping are avoiding the allergen, taking medicines such as antihistamines, decongestants, herbal or homeopathic remedies, or undergoing immunotherapy—a series of injections of weak solutions of the allergen that over time desensitizes the body and reduces the reaction.

Over the last generation there has been a rise in seasonal allergies and asthma in urban areas around the world. Researchers have puzzled why, and theories abound. Exposure to pollutants and genetics play roles.

The 2012 Canadian Urban Allergy Audit, http://file.marketwire.com/release/PolleNation_Report.pdf , commissioned by allergy medication manufacturer Reactine, has added urbanization and “botanical sexism” to the list of likely suspects.

The audit was conducted by Thomas Leo Ogren, who developed the Ogren Plant Allergy Scale, which rates plants by their allergenic potential. (The scale is being used by U.S. cities and schools intent on developing allergy-friendly cities and public spaces). Ogren travelled to 11 cities across Canada and found that our big cities don’t have enough trees, that the male-female balance of trees is grossly out of whack, and that allergy-causing trees are plentiful in the urban forest.

Urban foresters believe the tree canopy ideally should cover 40 per cent of a community. The lungs of the city, the tree canopy removes allergens and carbon dioxide from the air, not to mention bestowing other benefits like cooling the urban landscape in summer and acting as windbreaks in winter. Of the 11 cities visited none came close to the ideal. Ottawa and Regina topped the list in canopy cover at 27 per cent and 24 per cent; Victoria, Vancouver and Halifax came in at 20 per cent; Montreal 18 per cent, Toronto 17 per cent, Edmonton 15 per cent, Saskatoon 10 per cent and Calgary, a mere five per cent. Even London, Ont., a.k.a. the Forest City, has a canopy covering only 24.7 per cent of its area.

Overwhelmingly, that canopy is made up of male trees. Most of the bushes and plants in city yards and parks are also male. Urbanites favour male plants because they are less messy—no seeds and fruit to clean up. But male plants produce pollen. The trees in canopies of cities studied are between 74 and 94 per cent male. Planting more female trees could help reduce the amount of pollen we’re exposed to, not only because female trees don’t produce pollen, but they trap pollen from male trees.

Our cities are home to many trees high on the allergy scale, including male landscape yews, junipers, Manitoba and red maples, poplars and aspen, oaks, golden willows. Less allergenic choices are the females of those species, plus mountain ash, crabapples, pine, spruce and larch.

Sadly, allergenic trees have often been chosen for schoolyards and backyards because they don’t produce messy fruit or seed pods for kids to walk in, roll on or throw at each other. But it does increase the amount of pollen kids are exposed to. You don’t have to be a scientist to realize reducing male trees by half would also at least halve the amount of tree pollen floating around, or to suspect a connection between children’s immature immune systems, concentrations of pollen where kids congregate, and increasing allergy rates. Cities across North America are taking notice and planning allergy-free school yards, parks and green zones. The Canadian Urban Forest Network  http://www.tcf-fca.ca/programs/urbanforestry/cufn/pages.php?lang=en&page= aboutus has a list of cities and the various ways they’re sprucing up their tree cover.

But replacement of urban trees is a long-term proposition. We can make changes in our own backyards that can improve the health of our families and our neighbours. One U.S. study showed a pollen-producing tree in your own yard exposes you to 10 times more pollen than a neighbour’s tree a few houses away, so choosing non-allergenic trees and shrubs for your yard makes sense.

Odd Body Fact

Drippy noses and sneezes are a bane to allergy sufferers, but they are both important to our immune systems. It protects the respiratory system by trapping dirt, bacteria and pollen and prevents it from entering the lungs. Normally our bodies produce about a litre a day, but inhaling irritants—cigarette smoke, dust, pollen—causes mucous production to ramp up. When an irritant like pollen enters the nose, the body tries to get rid of it—fast. The irritant stimulates the trigeminal nerve, causing a sneeze. Material released by a sneeze can travel at least 150 kilometres per hour (the speed, hopefully, clocked by remote sensors).


Advertisement


Sign up today for a FREE download of Canada’s War Stories

Free e-book

An informative primer on Canada’s crucial role in the Normandy landing, June 6, 1944.