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Guideline # 5
Minimize dust during normal cleanup operations.
There is a logical, yet incorrect conclusion that leaf blowers generate vast amounts of dust. Of course, they can, but when used properly, they contribute very little to the particulate matter in the air. It is all in the way one holds the nozzle and the amount of air generated.
To begin with, one should ensure that whatever dust is created should not be allowed to travel toward any
nearby person or neighboring property. Understand
that there are times when the blower simply should not be used. The job should be performed at a time when no one is around or when the prevailing wind is in a favorable direction.
To minimize the generation of dust, hold the nozzle above the ground and at a distance from the debris such that the airflow at the ground is only sufficient to move the material you want moved. In dusty areas and when using larger blowers, the nozzle must be held even higher above the ground with an aiming point farther away from the operator. Air velocity is what dislodges the material to be moved and air volume is what keeps it suspended once it is in the air. Practice this by starting with the nozzle well above the ground and then lower it to where it picks up the debris but not the dust.
You may think that dust is very light and easily lifted into the air. In reality, it is very heavy per unit volume. A good example is cement dust. One cubic yard of concrete is 1000 pounds heavier than one cubic yard of sand, yet because the particles of cement are very fine, a leaf blower can lift them if enough air movement is applied. A leaf, a blade of grass or a paper cup, on the other hand, has a weight or density hundreds of times lower than dust. One can find the correct airflow speed and volume to move only the leaf and not the dust with only a little practice.
The measured and published velocity of any commercial leaf blower is the highest value one can measure. That means it is measured at the end of the nozzle. The actual velocity at the ground can be much less without slowing the engine. The airflow speed falls off rapidly as it travels away from the nozzle and spreads out over a wide area. Skilled blower operators direct only enough air to move the unwanted debris, controlling the velocity, volume and position of the nozzle to avoid kicking up any dust.
The concept of a larger blower generating more dust is incorrect. Large blowers are intended for cleaning large areas and can be handled in such a way that very little dust is generated. It takes practice to do this, but it can and must be learned to avoid this complaint.
