Glyphosate
Portland Public Schools
weedkiller Roundup
By Aimee Green and Mark Friesen
for The Oregonian/OregonLive
August 28, 2022
The controversial weedkiller glyphosate is the most frequently sprayed herbicide on Portland Public Schools properties, a review of public records from the past three school years shows.
The district sprayed glyphosate -- often sold under the brand names Roundup or Ranger Pro -- at about 20% of its elementary and middle schools and 70% of its high schools. The district applied the chemical along fences and around trees, in landscaped beds, on ball fields and on asphalt gravel lots and on walkway cracks.
Over the past three school years, Franklin High in Southeast Portland has been sprayed with the glyphosate-based weedkillers Roundup and Ranger Pro more than any other property within Portland Public Schools.
The school district's use of Roundup and other glyphosate-based weedkillers has fluctuated significantly - from about 13 gallons in 2019-20, to 20 gallons in 2020-21, to 10 gallons in 2021-22. Herbicides are widely seen as a faster and cheaper way to eliminate weeds, especially in a tight labor market.
Additional on-line research by Byron Caloz
According to the PPS ( https://www.pps.net/Page/2218) on a webpage discussing its "Integrated Pest Management" program, its staff occasionally "must use herbicides, primarily along fence lines and in areas that are inaccessible to mowers or other mechanical equipment." To reduce herbicides, the district depends on volunteers to clear weeds rather than hiring workers.
Oregon Statutes require IPM programs which use "low-impact pesticides." In this context, pesticide also includes herbicides. The statute considers such chemicals low-impact if the words "warning" or "danger" are not included with the list of active ingredients or have active ingredients which are classified as a probable or known cause for creating cancer in humans.
Brian McDonald and Alec Kowalewski at Oregon State University's Horticulture Department wrote the current definitions of what are low-impact herbicides in 2013.
For non-selective herbicides they said that Round Up Pro Concentrate and Round Up Pro Max were "low-impact", as were 8 other brands, all of which used glyphosate compounds as active ingredients.
Various agencies look to both OSU and the U.S. EPA for guidance whether herbicides are cancer causing, developmental toxins, mutagenic or cause reproductive effects. Some also include "other reliable sources or studies" such as the East Multnomah Soil and Water Conservation District. EMSWCD also wants chemicasls with low acute toxicity and that are biodegradable.
Portland, Oregon resident and inventor Michael Peterson says on a webpage: "The health concerns regarding the use of glyphosate are well documented and reflect a growing concern regarding our overuse of chemical herbicides to keep our yards, gardens and municipal parks free from weeds." Since 2007 he has been working on an organic weed killing sprayer which he says kills small to medium sized weeds at a rate similar to glyphostate-based chemicals but without any toxic residue or danger. His device, HotZot, uses jets of 200 degree Fahrenheit water to kill as many as 300 weeds an hour.
The state of California and a committee with the World Health Organization believe glyphosate is either carcinogenic to humans or is probably carcinogenic.
Yet both the Portland Public Schools and the city of Portland continue to use it.
Part of the reason why public agencies use it is because of the low-impact list from OSU and from analyses by various experts. The U.S. Environmental Protection Agency said in 2017 that the herbicide is "not likely to be carcinogenic to humans." The European Food Safety Authority says the same thing.
Legal challenges from humans who developed non-Hodgkin lymphoma have resulted in court judgments against the manufacturers of glyphosate chemicals. University of Washington researchers said in a 2019 study that the chemical raises the cancer risk for anyone exposed to it by 41%. The authors of the report also looked at all published studies to that point.
So, with some experts concerned with the chemical, it would appear that it at least it is probable glyphosate causes some forms of cancer in humans.
The questions not yet answered are: what kind of exposure is needed to cause cancer. A biosciences professor at the University of Central Lancashire, Francis Martin, told CNN in 2019 that there need to be "new, well-designed and robust studies at appropriate exposure levels." Martin said such the number of such studies has been "pathetically small."
weedkiller Roundup
By Aimee Green and Mark Friesen
for The Oregonian/OregonLive
August 28, 2022
The controversial weedkiller glyphosate is the most frequently sprayed herbicide on Portland Public Schools properties, a review of public records from the past three school years shows.
The district sprayed glyphosate -- often sold under the brand names Roundup or Ranger Pro -- at about 20% of its elementary and middle schools and 70% of its high schools. The district applied the chemical along fences and around trees, in landscaped beds, on ball fields and on asphalt gravel lots and on walkway cracks.
Over the past three school years, Franklin High in Southeast Portland has been sprayed with the glyphosate-based weedkillers Roundup and Ranger Pro more than any other property within Portland Public Schools.
The school district's use of Roundup and other glyphosate-based weedkillers has fluctuated significantly - from about 13 gallons in 2019-20, to 20 gallons in 2020-21, to 10 gallons in 2021-22. Herbicides are widely seen as a faster and cheaper way to eliminate weeds, especially in a tight labor market.
Additional on-line research by Byron Caloz
According to the PPS ( https://www.pps.net/Page/2218) on a webpage discussing its "Integrated Pest Management" program, its staff occasionally "must use herbicides, primarily along fence lines and in areas that are inaccessible to mowers or other mechanical equipment." To reduce herbicides, the district depends on volunteers to clear weeds rather than hiring workers.
Oregon Statutes require IPM programs which use "low-impact pesticides." In this context, pesticide also includes herbicides. The statute considers such chemicals low-impact if the words "warning" or "danger" are not included with the list of active ingredients or have active ingredients which are classified as a probable or known cause for creating cancer in humans.
Brian McDonald and Alec Kowalewski at Oregon State University's Horticulture Department wrote the current definitions of what are low-impact herbicides in 2013.
For non-selective herbicides they said that Round Up Pro Concentrate and Round Up Pro Max were "low-impact", as were 8 other brands, all of which used glyphosate compounds as active ingredients.
Various agencies look to both OSU and the U.S. EPA for guidance whether herbicides are cancer causing, developmental toxins, mutagenic or cause reproductive effects. Some also include "other reliable sources or studies" such as the East Multnomah Soil and Water Conservation District. EMSWCD also wants chemicasls with low acute toxicity and that are biodegradable.
Portland, Oregon resident and inventor Michael Peterson says on a webpage: "The health concerns regarding the use of glyphosate are well documented and reflect a growing concern regarding our overuse of chemical herbicides to keep our yards, gardens and municipal parks free from weeds." Since 2007 he has been working on an organic weed killing sprayer which he says kills small to medium sized weeds at a rate similar to glyphostate-based chemicals but without any toxic residue or danger. His device, HotZot, uses jets of 200 degree Fahrenheit water to kill as many as 300 weeds an hour.
The state of California and a committee with the World Health Organization believe glyphosate is either carcinogenic to humans or is probably carcinogenic.
Yet both the Portland Public Schools and the city of Portland continue to use it.
Part of the reason why public agencies use it is because of the low-impact list from OSU and from analyses by various experts. The U.S. Environmental Protection Agency said in 2017 that the herbicide is "not likely to be carcinogenic to humans." The European Food Safety Authority says the same thing.
Legal challenges from humans who developed non-Hodgkin lymphoma have resulted in court judgments against the manufacturers of glyphosate chemicals. University of Washington researchers said in a 2019 study that the chemical raises the cancer risk for anyone exposed to it by 41%. The authors of the report also looked at all published studies to that point.
So, with some experts concerned with the chemical, it would appear that it at least it is probable glyphosate causes some forms of cancer in humans.
The questions not yet answered are: what kind of exposure is needed to cause cancer. A biosciences professor at the University of Central Lancashire, Francis Martin, told CNN in 2019 that there need to be "new, well-designed and robust studies at appropriate exposure levels." Martin said such the number of such studies has been "pathetically small."