On July 7, 2017, California became the first state in the nation to list Glyphosate, the active ingredient in Monsanto’s Roundup weed killer, to the state’s Proposition 65 list of chemicals known to cause cancer.
OEHHA’s decision was pursuant to the requirements of the Safe Drinking Water and Toxic Enforcement Act, better known as California Proposition 65, a ballot initiative approved by voters in 1986 to address toxic chemical exposure concerns. Prop 65 requires the State of California to publish a list of chemicals known to cause cancer, birth defects or other reproductive harm.
OEHHA implements Prop 65’s toxic chemical list requirements through a series of related regulations. Health & Safety Code Section 25249.8(a) states: The Prop 65 “list shall include … those substances identified in Labor Section 6382(b)(1)…”
Labor Section 6382(b)(1) identifies: “[s]ubstances listed as human or animal carcinogens by the International Agency for Research on Cancer (IARC)…”
California Code of Regulations Section 25904(b) states: “[a] chemical or substance shall be included on the [Prop 65] list of it is classified by [IARC] … as: … (2) Probably carcinogenic to humans (Group 2A).”
Thus, in March 2015, when IARC classified glyphosate as a “probable human carcinogen,” the foregoing legislation permitted OEHHA’s adopting IARC’s findings as a basis for adding glyphosate to the Prop 65 list.
Once listed as carcinogen by IARC, warnings were required to prevent unwitting exposure to glyphosate. To wit, Health & Safety Code Section 25249.6 states: “No person in the course of doing business shall knowingly and intentionally expose any individual to a chemical known to the state to cause caner of reproductive toxicity without first giving clear and reasonable warning to such individual…”
California Glyphosate Warning Timeline
A protracted process starting with the 2015 IARC report led to the final decision to list a California glyphosate warning in accordance with Prop 65. The following timeline shows how California EPA arrived at its decision:
- March 20, 2015: IARC issued its report on glyphosate, concluding that the chemical is probably carcinogenic to humans. The IARC report was based, in part, on studies of exposures to glyphosate in several countries around the world, and it traced the health implications from exposure to glyphosate since 2001.
According to the report, non-Hodgkin lymphoma (NHL) and other hematopoietic cancers are the cancers most associated with glyphosate exposure. The report further concluded that glyphosate exposure caused DNA and chromosomal damage in human cells, as well as genotoxic, hormonal and enzymatic effects in mammals.
- Jan. 21, 2016: Monsanto filed a lawsuit against OEHHA over the agency’s intent to add glyphosate to Prop 65 list. Monsanto challenged the statutory basis underlying OEHHA’s intent to list glyphosate, arguing that the decision ceded authority to an “unelected, undemocratic, unaccountable foreign body.”
- March 10, 2017: Judge Kapetan formalized her ruling, which allowed Calif. EPA-OEHHA to proceed with its intent to list glyphosate as a carcinogen in accordance with Prop 65 and to move toward a possible California glyphosate warning on Roundup and other glyphosate herbicides.
In her ruling, Judge Kapetan wrote:
“…the Labor Code listing mechanism does not constitute an unconstitutional delegation of authority to an outside agency, since the voters and the legislature have established the basic legislative scheme and made the fundamental policy decision with regard to listing possible carcinogens under Proposition 65…”
- March 22, 2017: Monsanto appealed and requested a stay of the Superior Court ruling.
OEHHA also proposed a No Significant Risk Level (NSRL) for glyphosate of 1100 micrograms per kilogram of body weight per day, determining that exposures below that level would be given “Safe Harbor” and would be exempt from the warning requirement.
- May 10, 2017: Due to a substantial number of requests and interest in the issue, OEHHA scheduled a hearing for June 7, 2017.
Baum Hedlund submitted a public comment highlighting the various issues with the NSRL and urged OEHHA to consider epidemiological literature, additional animal bioassays and the carcinogenicity of the Roundup formulation actually used by consumers.
Some advocates wanted to see a California glyphosate warning on all bottles of Roundup and other glyphosate herbicides if not an outright ban.
- June 15, 2017: Court of Appeal denied Monsanto’s request for a stay of listing following the Superior Court ruling in Monsanto v. OEHHA.
- June 20, 2017: Monsanto filed an administrative petition with OEHHA, pursuant to Title 27 of the California Code of Regulations Section 25904(e), requesting the agency to “refrain from adding Glyphosate to [Prop 65].”
Monsanto argued that an unpublished study (which showed no evidence of link between glyphosate and cancer) had not been disclosed to IARC and would have lowered the classification if IARC had considered the study results in its final evaluation.
The study suffered from fundamental problems which rendered it far from determinative on the issue of causation. IARC only considers published, peer-reviewed literature and the study was not published (most likely due to its flaws).
- June 22, 2017: California Supreme Court denied Monsanto’s request for review and stay of listing the California glyphosate warning.
- June 26, 2017: OEHHA announced that effective July 7, 2017 glyphosate will be listed in accordance with Proposition 65 as known to the state of California to cause cancer via the Labor Code mechanism.
- July 7, 2017: OEHHA officially added glyphosate to the list of chemicals known to the state to cause cancer. OEHHA has yet to decide if it will require a warning on Roundup and other glyphosate herbicides. Per the Huffington Post, an OEHHA spokesman said it is possible that OEHHA could change the NSRL for glyphosate as the agency reviews the input it has received from outside parties. More than 10,600 comments were submitted to OEHHA during the public comment period regarding the glyphosate NSRL issue.
Problems with the ‘No Significant Risk Level’ (NSRL) California Glyphosate Warning Exception
Proposition 65 prohibits a person in the course of doing business from knowingly and intentionally exposing any individual to a chemical that has been listed as known to the State of California to cause cancer or reproductive toxicity, without first giving clear and reasonable warning to such individual. However, reasonable warning is not applicable when exposures are “insignificant.”
Based upon a single mouse diet study, OEHHA proposed a No Significant Risk Level (NSRL) for glyphosate of 1,100 micrograms per kilogram of body weight per day, meaning that any level of glyphosate exposure below the NSRL would not require a warning.
There are several scientific, legal and public health issues raised by the proposed NSRL, which provides a Safe Harbor exemption from Prop 65’s warning requirement.
OEHHA Did Not Evaluate Human Epidemiology Data on Glyphosate Cancer Risk
The California Code of Regulations Section 25703(a)(2) requires that a quantitative risk assessment appraise the “quality and suitability of available epidemiologic data…”
According to Baum Hedlund attorneys, OEHHA has not fully complied with the statute by failing to review the abundant epidemiological literature on glyphosate carcinogenicity.
The following epidemiological studies demonstrate a significantly elevated risk of NHL among farmers:
Orsi, L., et al., Occupational exposure to pesticides and lymphoid neoplasms among men: results of a French case-control study, Occupational and environmental medicine 2009, 66: 291-298
Morton LM et al., Heterogeneity among non- Hodgkin lymphoma subtypes: The Inter Lymph non-Hodgkin lymphoma subtypes project. J. Natl. Cancer Inst 2014, 48: 130-144
Hardell, L., et al., Exposure to pesticides as risk factor for non- Hodgkin’s lymphoma and hairy cell leukemia: pooled analysis of two Swedish case-control studies. Leuk Lymphoma. 2002 May; 43(5):1043-1049
The following epidemiological studies link glyphosate exposure to elevated risk of NHL:
De Roos et al. (2003) reported that the use of glyphosate was associated with increased incidence of NHL.
Eriksson et al. (2008) reported that exposure to glyphosate was associated with increased odds for lymphoma subtypes and elevated odds of B-cell lymphoma and the subcategory of small lymphocytic lymphoma/chronic lymphocytic leukemia. The study also found that handling glyphosate for more than 10 years was associated with a significantly increased risk of NHL.
Pahwa et al. (2016) reported elevated risk of all NHL types with any glyphosate use and a dose-response effect was observed with greater use. The study also found that handling glyphosate for more than two days per year was associated with a significantly increased risk of NHL.
An analysis of Schinasi et al. (2014) reported increases in NHL risk with any glyphosate exposure.
Chang and Delzel, (2016) reported “marginally significant positive meta-RRs for the association between glyphosate use and risk of NHL.”
OEHHA Calculated Glyphosate NSRL Using a Single Rodent Diet Exposure Study
One rodent diet exposure study is not enough to ensure safe exposure levels for glyphosate. OEHHA should have considered additional animal studies, accounting for variable exposure doses used in studies which observed tumor incidence and the growth of lymphomas at significantly lower doses than the single rodent diet exposure study OEHHA relied upon.
The following rodent studies found incidences of tumor development:
- Wood et al. found Lymphoid hyperplasia at low and mid doses in male mice at 71.4 and 234.2 mg/kg-bw/day in a study where malignant lymphomas were significantly induced at 810 mg/kg-bw/day.*
- Lankas in a 1981 study where Lymphocytic hyperplasia was observed at 11 mg/kg-bw/day in Sprague-Dawley rats.**
- Lankas observed Testicular interstitial tumors in male Sprague-Dawley rats which demonstrated a significant trend and a significant pairwise comparison between control and the high dose of 31.49 mg/kgbw/ day.**
- Stout and Ruecker observed Pancreatic islet cell adenoma in male Sprague-Dawley rats demonstrating a significant pairwise comparison relative to controls at the low dose, 89 mg/kg-bw/day in 1990.***
* EPA Glyphosate Issue Paper 2016 page 81
** EPA Glyphosate Issue Paper page 74
*** EPA Glyphosate Issue Paper page 75
In addition to the above studies, eight additional tumor sites were found in previously unavailable data in several key animal studies related to glyphosate carcinogenicity. This data, which was not available to IARC when the agency issued its glyphosate report, further bolsters the original carcinogenicity findings and highlights the need for a proper California glyphosate warning.
Glyphosate Interferes with Human Microbiota
Glyphosate kills weeds by interfering with the “shikimate pathway,” a metabolic sequence that synthesizes vital amino acids. Glyphosate disrupts the shikimate pathway by interfering with 5-enolpyruvylshikimate-3-phosphate (EPSP), an enzyme that governs aromatic amino acid formation in higher plants, bacteria and fungi.
While Monsanto’s current Roundup® label says glyphosate targets “an enzyme found in plants but not in people or pets,” EPSP is, in fact, present in many beneficial bacteria that inhabit human mucous membranes, skin and gut. The current Roundup label disregards the millions of bacteria, fungi and other microorganisms in or on human mucous membranes, skin and the gut that rely upon the shikimate pathway glyphosate disrupts.
When glyphosate interferes with the microbiota cells that regulate numerous biological processes, serious health risks follow, including lymphomas.