It turns out that the great outdoors may not be so great after all. Those captivating summer scents – fresh-cut grass, clear country air, burning campfire – could be hotbeds of toxic chemicals, allergens and other signs of poor air quality.

Here's how to breathe a little easier this summer, no matter where you are or how you get there.

Road trips
Mould spores, exhaust, road dust and other pollutants blow into the car via the heating, ventilation and air-conditioning system, and passengers may come down with a headache, sneezing or irritation in the nose or throat as a result. To reduce the risk of breathing in too many toxins, open the windows to air out the car before you blast the air conditioner, and do so every so often during the trip. "It's always a good idea to have fresh air, especially on a long road trip where you've been cooped up in a car for a few hours," says Connie Choy, air-quality coordinator with the Ontario Lung Association. Pay attention to the cars around you, too. If you're travelling behind a car that is blowing a bluish-brown smoke, change lanes to avoid it.

Airplanes
The air-quality debate in airline cabins has resurfaced after two former British Airways pilots died within days of each other this past winter, allegedly from aerotoxic syndrome. What does this mean for occasional passengers? Refreshed 15 times an hour, cabin air is a combination of filtered, recirculated air and fresh, compressed air that is pumped from the engine. Sometimes engine fumes contaminate this air, an "event" that a British government committee reported occurred on one per cent of flights. "Generally the fumes shouldn't remain in the air too long, but it does happen," says Choy. Symptoms include headache, nausea, itchy eyes, sore throat and feeling sick. There's not much you can do about it, though. If you're travelling by plane, Choy suggests turning on the air directly over your seat so that fresher air disperses the odour.

More common issues from air travel include dry air and pet allergens. Both aggravate allergies and asthma, and can cause breathing problems and irritation in the nose and throat. Always check if the cabin is pet-free before boarding, keep allergy medication within reach and drink plenty of water.

Smog
While smog can occur at any time of the year, its visible haze appears during the warmer months, when the heat and sun react with vehicle exhaust, factory emissions and other pollutants. Inhaling this ground-level ozone can lead to breathing problems, allergic reactions, lethargy, chest tightness, irritated eyes, nose and throat, and lung damage, says Choy. It can also be fatal: Health Canada estimates that some 5,900 deaths per year are linked to air pollution in eight Canadian cities (Quebec City, Montreal, Ottawa, Toronto, Hamilton, Windsor, Calgary and Vancouver). Check the air quality every day and plan your activities accordingly. Remain in a cool, well-ventilated place on smoggy days. If you must go outside, stay in the shade and away from heavy traffic, drink lots of water and don't overexert yourself.

The suburbs
Beautiful green laws may come at a toxic price. Breathing in pesticide fumes can be problematic for anyone, but especially for those who have chemical sensitivities or lung disease. These fumes may cause a variety of symptoms, including headaches, shortness of breath, vomiting and loss of consciousness, as well as long-term effects like cancer. Some areas of Canada have pesticide bans, but not all. Companies that spray with pesticides should leave a sign telling people not to cross the area for 24 to 48 hours, says Choy. "But if you smell a musty odour, don't linger too long and don’t let pets on the grass. Their fur can absorb the chemicals and then they bring them into the house."

Cottage country
A visit to cottage country is marked by big-sky vistas, dense forests and lush plants. However, those flowering plants – whether they're trees, grasses or weeds – release pollen, a powdery grain carried by the wind and used to cross-pollinate with other plants. If breathed in, pollen can trigger seasonal allergic rhinitis – better known as hay fever. Typical symptoms of hay fever include watery eyes, runny nose, nasal congestion, itchy throat and sinus pressure. Check pollen reports on a regular basis and remain indoors and keep windows closed when the count is high. If you do venture outside, be sure to shower when you go back inside in order to wash off any pollen, and change into fresh clothes.

Campfires
Roasting marshmallows over a crackling fire is a time-honoured summer tradition. But a recent study conducted in British Columbia found wood smoke to be the most serious kind of air pollution in the province, leading to more illness and deaths than smog. Wood smoke is composed of hundreds of chemicals, says Choy, and breathing them in can cause a host of issues, from sneezing and dizziness to breathing and cardiovascular problems to seizures, coma and respiratory failure. To reduce your risk, use properly treated and dry wood, build a fire with kindling rather than newspaper and refrain from tossing in garbage, plastics, cardboard and toxic materials. Also remember to always check bylaws, burn bans and the venting index.