Droughts Evil Twin

Posted on Oct 3, 2016

Drought means changing not only our outdoor water use, but also the way we tend our gardens. In the Do Not Do category should be leaf blowers. Which, dry soil and drive mold and contaminants into the atmosphere and, count on it, into our lungs. Most gravely at risk are gardeners, closely followed by children, the elderly, pets and wildlife.

Yet, leaf blowers are an everyday occurrence in drought stricken Los Angeles. They literally scour the earth: stripping off topsoil, desiccating roots, and killing vital soil-dwelling organisms, while, at the same time, propelling into the air clouds of dirt, dust and dangerous contaminants: volatile compounds, mold and fungal spores, weed seeds, insect eggs, pollen, molecules of the myriads of toxic chemicals people spray and sprinkle on their gardens, trees, and lawns, not to mention bird and rodent feces.

Is avoiding the rake or broom really worth the negative consequences?

Let’s break it down…

Human

Leaf blowers cause damage to our lungs (not just the operators of the machinery are affected), polluting the air and exacerbating allergies. The American Lung Association recommends avoiding gas-powered leaf blowers for our health. This air pollution comes from the dust they stir up; particulate matter is a recognized pollutant on its own, and it also may contain pollens, animal feces, landscape chemicals, lead, mold spores, and other contaminants that are unhealthy for us to breathe.

Additional pollution comes from their exhaust fumes, spewing out carbon monoxide, nitrogen oxides, and hydrocarbons (CO, NOx, and HC) at levels greater than automobiles. Because they are designed to be air-cooled, the engines release 100% of their tailgate emissions directly into the environment, and since they also burn fuel very inefficiently, a leaf blower running for one hour emits as many hydrocarbons and other pollutants into the atmosphere as a car driven at 55 mph for 110 miles.

Last but certainly not least, they shatter our peace. Exposure to noise can interrupt sleep, depress our immune systems, increase anxiety and hostility, lower our productivity, aggravate heart disease, cause gastrointestinal distress, increase birth defects, and reduce cognitive development in children.

Plants

A leaf blower’s very reason for being is to remove fallen leaves. This isn’t always healthy for your plants. Though lawns cannot survive under a thick layer of leaves, other plants (especially trees and woodland plants) will thrive with an undisturbed layer of leaf litter, which protects roots, fosters soil life, and is decomposed into nutrients that feed the plants. Consider that wind blows from the nozzles of these machines at speeds in the range of 180 mph. Winds of that force do not occur naturally on Earth, except inside hurricanes and tornadoes. Worse, still, because the wind is carrying away large quantities of heat from the hyperactive engine, it is also very hot and exceedingly dry. Subjecting everything at ground level to blasts of hot, dry, hurricane-force winds would be ill-advised at any time, since it cannot fail to injure plants and open pathways for pests and disease, while at the same time aiding and abetting the pathogens by distributing them over the widest possible area. In the summer, though, when the air is hot and the ground is dry and the plants are dehydrated and badly stressed to begin with, subjecting them to tornadic blasts of hot, dry air is, nonsensical, to put it kindly.

Animals

Leaf blowers interfere with animals’ ability to communicate with each other in order to find mates, hunt, and avoid predators. Removing leaf litter destroys the habitat of many beneficial insects.

Soil

Leaf blowers blow away not just leaves but topsoil, exposing the ground to further erosion and colonization by wind-blown weed seeds. Blasts of hot, dry air (and the removal of protective organic matter on top of the soil) destroy the top layer of soil microbial life, which is the most active in powering the soil food web.

What should we do instead?

If you don’t do your own gardening — few Angelenos do — but leave it to a weekly team, talk to the ‘gardeners’. Ask them to leave any fallen leaves or grass in place rather than bagging it and putting it in your green bin. If they want more money and in fact deserve it, either pay them more or reduce the scope of work in an equitable way.  Insist that they under no circumstances use a leaf blower on any exposed soil or mulch, something that will at once dry out expensively irrigated soil and aerosolize dust. Because you might be at work and don’t see it doesn’t make it any less damaging for your landscape or the baby sleeping next door. With this gravest drought on record comes what bodes to be a lethal asthma season.