leaf blowers zero air pollution
research regarding leaf blower laws

Download the full survey as: HTML (592k zipped) | Word (772k) | PDF (652k)


Survey 99


STUDY PROPOSAL RE BLOWERS Only Version dated 5/2/99   Purpose of Study: To determine the impact of use of leaf and debris blowers on the mental and physical health of the user, and other employees or persons working and living in the vicinity. Where noise and air pollution from Particulate Matter ("PM") is being tested, it would be advantageous to include, as well, all devices whatsoever that operate on the principle of blowing leaves, grass clippings and related debris.Study considerations:

  1. All aspects of the use of each method should be considered, from the purchase of fuel, loading fuel, spillage and spillage fumes, preparing for use by starting and mounting the blower, including the time the blower is running compared to the time it is actually used, and maintenance.
  2. Subjects will not be apprised of purposes of study.
  3. Observations and monitoring of Workers using blowers in the "real world" without being aware they are being studied should be the basis for estimating how study results will impact care for residential properties, large and small.
  4. Both those who oppose and those who promote use of leaf blowers should be equally represented on a Task Force and encouraged to give their feedback to a proposed study before it is carried out. These people will be sensitive to what has been left out of previous studies, which may render those studies inaccurate.

Terms and Definitions:

  1. The all-inclusive term "Fuel" or "Power Source" should be used, and as many as possible fuels should be tested. Now these include gasoline, methanol, electricity.
  2. "Worker" means anyone using a blower and may include those working with the user. This term may mean gardeners, homeowners, residents, or anyone else.
  3. "Others" means anyone who is not a Worker as defined above who are seen or unseen by the Worker, who are inside, outside, or walking past who can smell or hear the device, or be subject to fumes and air pollution emissions, dust, particulate matter and other dislodged airborne debris caused by the use of the device.
  4. "Hand Tools" means rakes, brooms, and other tools which do not require sources of power other than physical action. Worker and Others: Because the subject of leaf blower vs other methods of debris and garden cleanup seriously affects Workers and Others, studies which are conducted to establish facts will only be valid if they take both groups into consideration. Factors which seem to impact only the Worker or only the Others actually have an impact on both groups.  


Distances from the source of air pollution and noise make a difference in mental and physical health, including factors such as fatigue, psychological mood. These factors, in turn, impact thinking, communication, and therefore, performance. Depending upon what you are studying, it may be more advantageous to be nearer or farther from the source. Taking a measurement at only one given distance is not helpful. Studies should monitor impact at several distances:

Upon the Worker using the cleanup tool, anyone within 10 feet (since homes and open windows may be 5 feet from a work area), the 50 feet which has been established for noise monitoring purposes, and whatever the final distance might be before a cloud of dust might settle in a typical neighborhood on a breezy day to be at least 150 feet. Other studies show the particulate matter as measured on a city-wide basis over a period of time. We need to know how people are impacted based on Workers using blowers in specific areas at specific times and for generally the same length of time, and usually on a regular weekly schedule. In the planning stage, request opinion of the Lung Association and Asthma associations, to determine if this study might also address some of their concerns, as it is planned or with slight modifications or additional record keeping.  


    1. Study of PM and emissions should include their drift under various weather conditions and airflow.
    2. Time on task, and therefore expenditure of fuel, should consider how long it takes to blow leaves and debris in dry areas vs wet areas, and off of hard, smooth or rough surfaces such as walkways and driveways, grass, and bedding areas; compacted dirt, loose dirt, gravel. Under normal operating conditions, how long the blower is actually running as compared to how long it is actually in use.
    3. Differences between use in public use lands (schools, parks, golf clubs, shooting rangers, public building exteriors) and residential.
    4. Compare blower use time for various chores: clean up of wet and dry paper, large debris, large and small leaves, wet and dry grass and leaves, pods, palm dates and dirt, small pebbles, dust.
    5. Analyze contents of dust and particulate matter from various locations; e.g. near highways, highly fertilized, composted areas. What is going into the air from various settings. For instance, one residential neighborhood vs a public land use area.
    6. Compare use techniques; i.e. leaves and debris blown straight ahead, or up against a curb, solid wall or fence with spacing between boards.
    7. Compare emissions at various blower speeds, velocity and/or volume.
    8. In addition to known respiratory problems associated with high Particulate Matter ("PM"), research existing studies and report on the dangers or lack of dangers of inhaling dried dog, bird and other animal feces, insecticides, oil and gasoline residue and other components of PM.


Studies which compare various sources of energy (gasoline, electricity, and other fuels for machines, and physical activity for machines or water, rakes and brooms) should consider noise pollution, air pollution, ground pollution, and the physical affects upon Workers of using all methods.


Time considerations should take into account all aspect of the use of blowers, as noted in page 1 "Study Considerations" #3 above.


Tools should be monitored as they are commonly used by both experienced and inexperienced Workers, since it must be assumed that recommendations from this study may be read, but not followed by all future users. The best tool for the job. Combining machine and physical activity.

Short and Long-term Health Considerations

Re: Workers:

  1. Fuel emissions from an operating machine;
    Spillage vapors when filling a tank.
  2. Physical stress in starting, lifting, mounting, and wearing and using a blower;
  3. Noise levels at normal use distance from Worker’s ears
  4. Particulate Matter height, time to settle, under various conditions, on various surfaces.
  5. Physical activity necessitated by filling tank, starting, mounting and using and/or carrying the blower, removing and storing.
  6. Mental stress regarding difficulty of use of various tools
  7. Worker compliance with manufacturer health and safety recommendations and understanding of which type earplugs and masks will protect them.
  8. Worker compliance with manufacturer recommendations regarding use distance from unprotected


Workers and Others

Re: Others: Fuel emissions at a 10 ft. and 50 ft. distance, from operating machines. Spillage runoff from filling a tank.

Fuel evaporation into air.

Sleep deprivation from noise specific to blowers Noise levels at 10 feet and 50 feet.

Particulate Matter height, distance, girth at 10 feet and 50 feet under various conditions, on various surfaces.

Time to settle back to earth.

Physical activity and stress of having to move to quieter, healthier location and of washing cars and housecleaning more often.

Allergy susceptibility over a period of time, as people who have no allergies develop them due to having reached their tolerance point.

Physical cumulative symptoms of allergies and asthma and need for medications based on ambient high PM. Fear and startle reactions, particularly in children and the elderly, caused by sudden loud noise.  

Mental Health Considerations

Re: Workers:

Pride in work skills tied to Worker expectations, employer expectations. Stress re judgments/opinions of self and others regarding use of power tools over hand tools. Hesitation/fear of discussing with employer documented increased work-time caused by change in work tools, as it relates to increased compensation and/or decreased expectations or decreased workload.    

Re: Others:

Results of sleep deprivation on work performance, coping levels, concentration of night shift workers, those suffering from illness, mothers of infants. Mental and Physical impacts of the startle reaction. Unacceptability of odors of fumes/emissions or noise may cause lack of concentration, anger, frustration. Interrupted communications cause lack of focus.

Distractibility. i.e.:

  • Stress re noise levels: 62 dB-87 dB at 20 feet is equal to a loud group address.
  • 65 dB is acceptable sound level for working around business machines and half of people trying to sleep will experience difficulty.
  • 70 dB causes people to have to shout at a distance of 6 feet and makes telephone conversation difficult.
  • 75 dB is sound level of maintenance shops and garages and a raised voice is required for conversants two feet apart.
  • 80dB makes it difficult to think clearly. May result in some stomach contraction and increase in metabolic rate.
  • 85 dB Shouted communications are possible at three-four feet. Telephone use difficult. Some hearing loss occurs in range of 300-1200 Hz. some cognitive performance decrement can be expected, especially where decision making is necessary.    

Goals and Results:

What are the goals of employers and Workers using various methods, and what are the final results? Do the results meet not only immediate, but long term goals. A thorough study would use the above considerations to compared all leaf blowers, whatever their fuel, with all other methods of leaf and debris cleanup, i.e. vacuums, mulching mowers, rakes, brooms, water. However, a comprehensive study limited to gas and electric blowers can set benchmarks for comparison with future studies regarding traditional and combined clean up methods such as rakes, brooms and mulching mowers.