• SNAP Tour of Organic Vegetable Garden
  • Learn to Keep Insects Out of your Crops
  • Learn to Manage Pests Naturally
  • Link to SK Organic Resources
  • Grow a Lush Garden Organically
  • Learn About Colony Collapse Disorder and How to Protect Bees
  • LIving Near Fields Increases Pesticide Exposure
  • SNAP Display at Event
  • Learn About Pesticides in Foods
  • Learn To Manage Weeds Without Chemical Pesticides

Pesticide Drift

Incidents of Pesticide Drift

view details »

also see pesticide fact sheets/dicamba 

Adverse Impacts of Pesticide Drift in Pineapple Production (Beyond Pesticides, December 12, 2018) 'Recent studies in Costa Rica identified evidence of increasing fur discoloration in black mantled howler monkeys ((Alouatta palliata) as a result of their exposure to sulfur-based pesticides.'  'In addition to altered pigmentation, excessive exposure often results in sensitivity to light, skin irritation and cancer. In addition to pigmentation bleaching, the use of pesticides in this region have adversely impacted surrounding communities resulting in increased incidences of epithelial damage, gastrointestinal issues, nervous system disorders, eye irritations and birth defects." 

Crop Damage from Monsanto’s Herbicide Dicamba Being Investigated in 17 States, Pointing to New Formulation Used in GE Fields  (Beyond Pesticides, August 8, 2017) More than 1,400 official complaints of crop damage related to the herbicide dicamba have been recorded across 17 states this year, leading some to question a new formulation of the chemical used in genetically engineered (GE) fields. Dicamba, a toxic pesticide prone to drift off the target site, has been used in agriculture for decades. However, new GE crops developed by Monsanto must be paired with specific formulations of dicamba, and until now many believed these drift incidents were the result of illegal formulations of dicamba being applied to fields. But the extent of damage now being observed, covering over 2.5 million acres, is casting doubt on this theory, and raising more questions as to whether the new dicamba formulation is actually the cause of the widespread drift damage. Fruits and vegetables, as well as other crops that are not genetically engineered to tolerate dicamba are often left cupped and distorted when exposed to the chemical. SNAP Comments: Last year, the incidents were due to illegal formulations used because the dicamba-resistant crops were put on the market before  the "less volatile" new formulations were approved for use. Looks like the new ones are no better.... Remember that all most chemical lawn herbicide formulations contin dicama as one of 3 active ingredients. 

Laws Governing Drift

view details »

Current regulations fail to define pesticide drift to include all forms of drift. The Canadian PMRA, as well as the U.S. EPA currently defines drift as the airborne, offsite movement of pesticides that occurs during and immediately after application. Yet PANNA's detailed analysis of monitoring data shows that, for volatile pesticides, the bulk of off-site movement occurs as pesticides volatilize after application (see figures in above reference and Secondhand Pesticides, Figure 3-1).

Spray drift, which is drift of particles and vapors that occurs during pesticide applications, is poorly regulated by current state and federal laws and regulations.
Post-application drift, which can occur for many days after an application, is barely regulated at all and is not acknowledged by U.S. or Canada, although apparently recognized since 1997 by Sask Agriculture and the PMRA-  (as seen above under Saskatchewan. Before the PMRA moved to Health Canada it was under Agriculture and Agri-Food Canada and Dr Wolf now works for the PMRA

CanadaInformation Note: Pesticide Spray Drift in Residential Areas  This document indicates that the PMRA does not adequately adress drift.This is the PMRA page accessed on May 5, 2010. Statements on spray drift is based on assumptions of proper use of pesticide products according to directions and only considers drift during application. Unfortunately, there is no ongoing Canadian or SK inspections of spray events of individuals, commercial applicators or farmers. A statement such as : "Although some pesticides can have strong odour that may be disagreeable, the odour itself is not harmful and tends to dissipate quickly." has no value for safety assessment . What is important is what in the formulation causes the odor, how toxic it is, how volatile the pesticide formulation is and how much active ingredient it contains. The latter will depend on the size of particles of the pesticide active ingredient itself, formulants used, spray equipment, and environmental conditions such as wind, heat and humidity. The PMRA statement also does not recognize the measurable daily cycle of evaporation off all sprayed surfaces (post-application or evaporation drift). This document indicates that the PMRA does not adequately adress drift.


U.S. steps to control drift

Illinois takes "baby steps" to reduce drift The voluntary initiative asks organic growers, beekeepers and others to register the locations of their lands with the website, and has the support of the state's agrichemical industry, which hopes to avoid any new, mandatory regulations ( PanUps Feb 26, 2010) Scroll down.

How much protection from drift is there in SK?

view details »

Sask Agriculture recognizes spray drift (as we see below) and that dangerous vapours can be produced even from dry deposit. However the introduction states: "Reports of spray drift in the mass media are damaging to the farming community and pesticide applicators, as they imply a lack of stewardship or environmental friendliness of farming practices." and "It is relatively easy to minimize drift by using a coarser spray. However, the primary reason for the spraying operation is to control the target pest, and this goal should not be compromised." (under 'Droplet Size and Efficacy') This seems to clearly set the priorities.

Spray Drift - Causes and Solutions  (Last Update: April 1997) SK agriculture. Written by: Dr. Tom Wolf, Agriculture and Agri-Food Canada, the same Tom Wolf who was heading the pesticide bylaw subcommittee of the Saskatoon Environmental Advisory Committee (SEAC) when they made a quick turn-around and chose not to support a pesticide bylaw for Saskatoon. More information on this issue is available from Sandra Finley at 2004-04-10 Tom Wolf, Health Canada scientist threatens to sue me. Response - the mafia uses threat of broken bones.
  • Self-propelled high clearance sprayers can travel at speeds up to 35 km/h (22 mph). Faster travel speeds cause a finer, more drift-prone spray to be produced, which stays in the air longer. The net result is a finer spray more exposed to winds that can move it off-target. 
  • Research tests have confirmed that faster travel speeds increase drift, even when applied with a coarser spray (Figure 4). 
  • "Some herbicides and insecticides are prone to vapour drift and can seriously hurt animals and humans. Vapour drift can occur even when there is no particle (droplet) drift, and even dry spray deposits can send vapours into the atmosphere." 
  • "Vapour drift increases with air temperature, therefore the application of volatile products should be avoided on, or just preceding, hot days."
  • It is also recognized that: 'At no or very low wind speeds, the drift cloud can move in an unpredictable direction and cause damage.'


view details »

Pesticide DRIFT Types of drift, science and policy, stories and action including how to measure. DriftCatcher results. Before ordering a drift catcher, check if it will be effective for the pesticide you want to monitor. (PANNA)

Pesticide Drift is not only responsible for damaged crops, but also of many incidents of pesticide exposure and/or poisoning both of agricultural workers and residents in the surrounding area.

How Dangerous Is Pesticide Drift? (Scientific American, Sept 17, 2012)

What is pesticide drift?

"Pesticide drift is any airborne movement of pesticides away from the intended target site, including droplets, dusts, volatilized vapor-phase pesticides, and pesticide-contaminated soil particlesDrift can occur both during and for many days, weeks, and even months after pesticide application. It can be very noticeable as a cloud of pesticide spray or dust or an unpleasant odor during the application. It can also be insidious—invisible to the eye, undetectable to the nose, but still capable of causing illness. As with secondhand cigarette smoke, these secondhand pesticides can cause significant adverse health impacts even at low levels. Drift is forced on others against their will and often without their knowledge."

"New analysis of pesticide drift in this report reveals that several widely used pesticides are regularly found far from their application sites at concentrations that significantly exceed acute and chronic exposure levels deemed “safe” by regulatory agencies. Virtually everywhere pesticides are used, they drift away from their intended target and can persist for days and even months after application."  

"U.S. EPA is required to assess all routes of pesticide exposure (food, water, air, and other) when it reevaluates a pesticide. However, it routinely dismisses second hand exposures from post-application drift as unimportant for non-fumigant pesticides, even though it has not yet evaluated California’s extensive set of air monitoring data that demonstrates the scope of the problem. Even for the highly volatile fumigants, risks from vapor drift have only been
evaluated for a single pesticide, Telone."
 The same is true of the Canadian Pest Management Registration Agency ( PMRA)

Second-Hand Pesticides: Airborne Pesticide Drift in California.(Californians for Pesticide Reform; report available on PANNA site)  Drifting pesticides can travel for miles, resulting in widespread toxic air pollution. In indoor environments, vaporized pesticides can persist for weeks after an application, concentrating in the air closest to the floor -- where children spend more of their time -- and condensing on plastic items such as children's toys. Pesticide drift causes acute poisonings and chronic illness, with children most at risk. The volatile pesticides PANNA studied include several fumigants, as well and the organo-phosphorous insecticide chlorpyrifosdiazinon, and the thiocarbamate herbicide molinate  the latter not licensed in Canada). Chlorpyrifos evaporates so easily that it is considered as a volatile organic compound in California. Chlorpyrifos is commonly used in SK agriculture under the trade name Lorsban