Environmental Facts

Gas Powered Lawn Mowers

According to the Government of Canada (One-Tonne Challenge) a gasoline powered lawn mower emits about 48 kilograms (106 lbs) of greenhouse gas in one season. Gas-powered lawn mowers are very inefficient, which means that despite their small size they produce a lot of air pollution. In fact, running an older gasoline-powered lawn mower for one hour can produce as much air pollution as driving a new car 550 kilometers. Source: Ministry of the Environment-Canada.

A gasoline-powered lawn mower run for an hour puts out about the same amount of smog-forming emissions as 40 new automobiles run for an hour. Source: California Environmental Protection Agency, Air Resources Board. May 20, 1999.

 

Air Pollution from Gasoline Powered Yard Equipment

A typical 3.5 horsepower gas mower, for instance, can emit the same amount of VOCs., NOx, CO – key precursors to smog – in an hour as a new car driven (550 km) or 40 new cars run for an hour, say industry experts. Source: South Coast Air Quality Management District. California, USA. March 31, 1996. Each weekend, about 56 million North Americans mow their lawns, using 800 million gallons of gas per year and producing tons of air pollutants. Garden equipment engines, (mowers, trimmers, edger’s, blowers) which have had unregulated emissions until very recently, emit high levels of carbon monoxide, volatile organic compounds and nitrogen oxides, producing up to 5% of the nation’s air pollution and a good deal more in metropolitan areas.

The conventional lawn mower pollutes as much in an hour as 40 late model cars for an hour. Source: EPA statistics for Replacing Gas Power Lawn Mowers Assuming that a typical car travels 18,000 km per year, 33 gasoline lawn mowers would produce as much pollution a car produces all year. The 56 million gasoline-powered lawn mowers generate as much pollution as 1.7 million cars. Traditional landscaping gasoline engines create Ozone, O3, a colourless, odourless gas at ambient concentrations which is a major component of smog.

Where is Ozone?

Ozone is found in two places in the Earth’s atmosphere. In the Earth’s upper atmosphere (stratosphere), the ozone protects life from harmful ultraviolet (UV) rays from the sun. High concentrations of ozone found in the Earth’s lower atmosphere (troposphere) are hazardous to life.

How is Tropospheric Ozone Created?

Ozone in the lower atmosphere (troposphere) is created through a series of reactions involving man-made chemical species such as Nitrogen oxides (NOx) and volatile organic compounds (VOCs). Chemical species that contribute to ground level ozone.

Ground Level Ozone

Ground level ozone pollution forms when emissions from gas-powered vehicles and lawn equipment (mowers/trimmers/blowers), industrial and chemical processes, and even household activities react with heat and sunlight. The highest ozone levels usually occur in summer months when temperatures approach the high 20c-30c and when the wind is stagnant or light.

Ozone in the air we breathe can harm our health—typically on hot, sunny days when ozone can reach unhealthy levels. Even relatively low levels of ozone can cause health effects.  People with lung disease, children, older adults, and people who are active outdoors may be particularly sensitive to ozone. Children are at greatest risk from exposure to ozone because their lungs are still developing and they are more likely to be active outdoors when ozone levels are high, which increases their exposure.  Children are also more likely than adults to have asthma. Breathing ozone can trigger a variety of health problems including chest pain, coughing, throat irritation, and congestion. It can worsen bronchitis, emphysema, and asthma. Ground level ozone also can reduce lung function and inflame the linings of the lungs. Repeated exposure may permanently scar lung tissue. Health Effects of Ground Level Ozone on Humans EPA

NASA and Ozone

NASA’s work involves a great deal of research in the service of society on our own planet, including studies of air quality. The Ozone Garden helps to educate people about ozone in our atmosphere. Their vision is to improve life here, to extend life to there, and to find life beyond. Ozone research contributes to the NASA vision by using satellite missions, such as Aura, to monitor the health of Earth’s atmosphere.

What Does Ozone Damage on Plants Look Like?

When exposed to high levels of ozone, many plants show damage on their leaves. Older leaves have the most damage. Plants with ozone damage have very fine colored spots on the upper surfaces of their leaves, and some leaves also turn yellow.

 

How is noise pollution related to air pollution?

Noise Pollution is a contamination of the quality of the sound in the air (Gasoline powered leaf blowers, construction sites).

Air Pollution is a contamination of the physical and chemical properties of the air (Exhaust from buses/planes, gasoline powered lawn mowers).

Both types of pollution, and pollution in general, is a disruption of the normal, homeostatic quality of the environment and detrimental to the quality of life.

Noise Pollution Comparison

Cordless electric mowers offer noise levels about 50% lower of those of their gas-powered counterparts. Source: Clean Air Foundation. Gasoline mowers generate noise over 100 decibels and hearing loss occurs around 90 decibels.

dB is an abbreviation for “decibel”. One decibel is one tenth of a Bel, named for Alexander Graham Bell.

The decibel is the unit used to measure the intensity of a sound. The decibel scale is a little odd because the human ear is incredibly sensitive. Your ears can hear everything from your fingertip brushing lightly over your skin to a loud jet engine. In terms of power, the sound of the jet engine is about 1,000,000,000,000 times more powerful than the smallest audible sound. That’s a big difference!

On the decibel scale, the smallest audible sound (near total silence) is 0 dB. A sound 10 times more powerful is 10 dB. A sound 100 times more powerful than near total silence is 20 dB. And a sound 1,000 times more powerful than near total silence is 30 dB.

Common sounds and their decibel ratings:

          •  Near total silence – 0 dB
          •  Whisper – 15 dB
          •  Normal conversation – 60 dB
          •  Cordless battery Lawnmower – 75 dB
          •  Gasoline powered lawnmower – 100 dB
          •  Gasoline powered leaf blower – 105 dB
          •  Car horn – 110 dB
          •  Rock concert or a jet engine – 130 dB
          •  Gunshot or firecracker – 140 dB

You know from your own experience that distance affects the intensity of sound. That is to say, if you are far away, the power is greatly diminished. All of the ratings above are taken while standing near the sound.

Any sound above 85 dB can cause hearing loss, and the loss is related both to the power of the sound as well as the length of exposure. You know that you are listening to an 85-dB sound if you have to raise your voice to be heard by somebody else. Eight hours of 90-dB sound can cause damage to your ears; any exposure to 140-dB sound causes immediate damage (and causes actual pain). See this page for an exposure “ruler.”

Ground Contamination

A big problem with gasoline lawn mowers is the fuel spilled during refueling. Lawn and garden equipment users in California alone spill 17 million gallons of fuel each year while refilling their outdoor power equipment. Source: Clean Air Foundation. If each gasoline-powered lawn mower spills one litre of fuel per season, there would be 56 million liters of fuel spilled and leach into our groundwater. This is the amount carried by about 2,800 tanker trucks.