GET THE DIRT ON 2-STROKES
- One hour on a typical snowmobile emits more air pollution than driving a modern car for a year.
- Studies show that a 2-stroke personal watercraft engine operating for seven hours produces the same amount of cancer-causing and smog-forming pollutants as an automobile being driven over 100,000 miles.
- Each year, marine 2-stroke motors spill 15 times more oil and fuel into waterways than did the Exxon Valdez.
- A 2-cycle gasoline-powered lawnmower pollutes as much in one hour as 40 new model cars. Nationwide, there are 89 million small 2-stroke engines in lawn and garden equipment directly exposing users to emissions.
What Can You Do?
You can reduce health risks to yourself and your family from exposure to 2-stroke engine exhaust while improving air quality in Minnesota:
- Choose cleaner alternatives in your home and yard. Use hand-powered or electric lawn and garden equipment. Help educate your neighbors that there are cleaner and quieter alternatives by loaning your equipment.
- If you use boats with outboard motors, personal watercraft, all terrain vehicles or snowmobiles, make sure they have 4-stroke engines.
- Ask your dealer to carry these cleaner, more efficient engines.
- Reduce recreational vehicle miles by canoeing, rowing, biking, hiking and cross-country skiing as forms of recreation.
- Support initiatives that improve air quality. It's easy to show your support through SierranAct, Sierra Club's email action alert system. To sign up: www.northstar.sierraclubaction.org.
- Join the Sierra Clean Air Committee. If you are interested in 2-stroke engines or air quality issues, please contact Cesia Kearns, 612-659-9124 or .
Dirty Engines Ruin All the Fun
Jump on a 2-stroke engine snowmobile this winter, and you may as well just dump ¼ of all the gas you use directly into the snow and air. Unlike automobile engines, which have been continuously modified for decades to increase efficiency and reduce emissions, the 2-stroke gasoline engine has not been improved significantly since it was introduced in the 1940s. 2-stroke gasoline engines, which take in fuel and emit exhaust in the same stroke, still dump from 25-30% of their fuel unburned directly into our environment.
2-stroke engines are still used in many vehicles throughout Minnesota - snowmobiles, personal watercraft, all terrain vehicles (ATVs), lawnmowers, garden equipment and outboard motors for boats. There are alternatives for each of these uses that are cleaner, quieter and better for the environment. There are hand-powered and convenient electric alternatives to some 2-stroke engines, like those in residential lawnmowers. Outboard motors, snowmobiles and personal watercraft can all be purchased with cleaner, quieter 4-stroke engines. According to U.S. EPA comparisons of 4-stroke and 2-stroke recreational vehicles, a 2-stroke engine emits 30 times more hydrocarbons (benzene, butadiene and polycyclic aromatic hydrocarbons) and 40 times the particulate matter as does the more efficient 4-stroke engine.
The pollution reductions created by choosing a 4-stroke engine, hand-powered, or electric alternative is significant. Mobile pollution sources contribute significantly to the risk of cancer, the emission of particulates that result in heart and lung disease, and the creation of ground level ozone (smog) that triggers asthma and causes respiratory irritation and lung impairment.
In Minnesota, it is estimated that 14% of benzene emissions from mobile sources come from off-road 2-stroke engines, while 10% comes from off-road 4-stroke engines. Benzene, emitted by off-road engines, is a known carcinogen. Benzene levels in many Minnesota cities are already high enough to cause health risks. The Minnesota Department of Health concluded in a study in 2000 that Minnesota children's total cancer risk from exposures to chemicals exceeded safe levels. Benzene from motor vehicles was the single chemical that contributed the largest share to each child's overall risk.
Looking at overall exhaust, 2-stroke engines are responsible for 32% of all of the mobile source hydrocarbons! This is highly disproportionate to their use. Hydrocarbons, disproportionately emitted by 2-stroke engines, react with sunlight to form smog, particularly in hot, sunny weather. Smog irritates the respiratory system and can have serious health effects on people with lung disease or susceptibility to asthma. Breathing smog can cause permanent lung damage to children.
CURRENT U.S. EPA RULES ON VEHICLES AND EQUIPMENT USING 2-STROKE ENGINES
SNOWMOBILES:
EPA rule reduces hydrocarbons (HC) and carbon monoxide (CO) 30%
starting in 2006, and 50% in 2012. The rule allows corporate
averaging, and has no cap on individual engines.
JET-SKIS AND OUTBOARD MOTORS:
EPA rule required 9-year phase-in (beginning in 1998 through 2006)
of 75% reductions in nitrogen oxides and hydrocarbons from new
engines. The rule allows corporate averaging, and has no cap on
individual engines.
** California has adopted standards that would reduce these emissions
above 90% in 2009.
LAWNMOWERS:
EPA rules has two phases: Phase 1 required a 30-35% reduction in
nitrogen oxides and hydrocarbons starting in 1997. Phase 2 is a 70%
reduction phased in between 2003 and 2007. Phase 2 allows corporate
averaging.
** California is in the process of adopting a stricter Phase 3 set
of standards.
SNOWBLOWERS:
Snowblowers are exempt from meeting the small engine nitrogen oxides
and hydrocarbons under a wintertime use exemption. There is a carbon
monoxide standard that is not difficult to meet for either 2-stroke
or 4-stroke engines.
These proposed rules are weak; they don't set standards clean enough to require the phaseout of 2-stroke engines. They also don't require an emissions labeling system to permit consumers to know how much pollution a vehicle emits before they buy it.