Westerman et al., 2005

Paula R. Westerman, Matt Liebman, Fabián D. Menalled, Andrew H. Heggenstaller, Robert G. Hartzler, Philip M. Dixon, “Are many little hammers effective? Velvetleaf (Abutilon theophrasti) population dynamics in two- and four-year crop rotation systems,” Weed Science, 53, 2005.

ABSTRACT:

Liebman, 2017

Matt Liebman, “Cultural techniques to manage weeds,” in Integrated weed management for sustainable agriculture, Ed: Robert Zimdahl, 2017, Burleigh Dodds Science Publishing.

SUMMARY:

The focus of this chapter is on cultural techniques that can also contribute to effective weed management strategies, including choice of crop density, crop arrangement, and crop genotype, and manipulation of initial crop size, soil fertility, and soil moisture conditions. Weed management strategies that make use of cultural factors seek to reduce weed density, resource consumption, biomass production and competition with crops. They also seek to prevent colonization of fields by weed species not previously present. Additionally, by altering the availability of light, water and nutrients in space and time, and by challenging weeds with allelochemicals, cultural tactics are intended to improve crop performance. FULL TEXT

Liebman and Gallandt, 1997

Matt Liebman and Eric Gallandt, “Many Little Hammers: Ecological Management of Crop-Weed Interactions,” In Ecology and Agriculture,” Ed: L.E. Jackson, 1997, Academic Press.

SUMMARY:

This is the first introduction of the phrase “many little hammers” to describe what is now known as integrated weed management, or IWM.  IWM relies on using a diverse assortment of weed control methods, possibly along with some herbicide use, along with changes in crop density and rotation to achieve weed control.  FULL TEXT

Liebman and Davis, 2009

Matt Liebman and Adam Davis, “Managing Weeds in Organic Farming Systems: An Ecological Approach,” In Organic Farming: The Ecological System, Ed: Charles Francis, 2009.

SUMMARY:

In this chapter, we describe major components of the weed management tool kit for organic farming, highlighting areas in which important advances have been made in the last decade. We then argue that instead of approaching the development of multitactic weed management strategies as a purely empirical, trial-and-error activity, the choice and deployment of weed management tactics should instead be informed by insights from ecological theory… Finally, we emphasize the need for ongoing dialog between empiricists and theoreticians and between scientists and farmers, so as to better direct scarce research resources and management time to where they are likely to be most beneficial. Multitactic weed management strategies informed by theory should be useful not just to organic farmers but also to conventional farmers who seek to reduce their reliance on herbicides due to concerns over herbicide resistance in weeds, rising production costs, and environmental and human health risks associated with herbicide exposure. FULL TEXT

Landrigan, 2018

Philip J. Landrigan, “Pesticides and Human Reproduction,” JAMA Internal Medicine, 2018, 178:1, DOI:10.1001/jamainternmed.2017.5092

SUMMARY:

Invited commentary by Managing Weeds for Healthy Kids science team member Dr. Landrigan reports that herbicide use has increased sharply, with glyphosate use up 250-fold from 1974 to 2014.  And, “measurable levels of multiple pesticides are found in the bodies of nearly all Americans…and pesticides are capable of causing a wide range of asymptomatic effects at levels of exposure too low to produce overt signs and symptoms.”  New theories suggest that long term exposure to pesticides cause this kind of subclinical toxicity.  Dr. Landrigan reviews the known linkages, including in utero chlorpyrifos exposure leading to neurodevelopmental deficits, and reproductive injury including adverse birth outcomes and birth defects. He recommends: “We need to overcome the strident objections of the pesticide manufacturing industry, recognize the hidden costs of deregulation, and strengthen requirements for both premarket testing of new pesticides, as well as postmarketing surveillance of exposed populations— exactly as we do for another class of potent, biologically active molecules—drugs.”  FULL TEXT

Laugeray et al., 2014

Anthony Laugeray, Ameziane Herzine, Olivier Perche,1,2 Betty Hébert, Marine Aguillon-Naury, Olivier Richard, Arnaud Menuet, Séverine Mazaud-Guittot, Laurianne Lesné, Sylvain Briault, Bernard Jegou, Jacques Pichon, Céline Montécot-Dubourg, and Stéphane Mortaud, “Pre- and Postnatal Exposure to Low Dose Glufosinate Ammonium Induces Autism-Like Phenotypes in Mice,” Frontiers in Behavioral Neuroscience, 2014, 8:390, DOI: 10.3389/fnbeh.2014.00390

ABSTRACT:

Glufosinate ammonium (GLA) is one of the most widely used herbicides in agriculture. As is the case for most pesticides, potential adverse effects of GLA have not been studied from the perspective of developmental neurotoxicity. Early pesticides exposure may weaken the basic structure of the developing brain and cause permanent changes leading to a wide range of lifelong effects on health and/or behavior. Here, we addressed the developmental impact of GLA by exposing female mice to low dose GLA during both pre- and postnatal periods and analyzed potential developmental and behavioral changes of the offspring during infancy and adulthood. A neurobehavioral test battery revealed significant effects of GLA maternal exposure on early reflex development, pup communication, affiliative behaviors, and preference for social olfactory cues, but emotional reactivity and emotional memory remained unaltered. These behavioral alterations showed a striking resemblance to changes seen in animal models of Autistic Spectrum Disorders. At the brain level, GLA maternal exposure caused some increase in relative brain weight of the offspring. In addition, reduced expression of Pten and Peg3 – two genes implicated in autism-like deficits – was observed in the brain of GLA-exposed pups at postnatal day 15. Our work thus provides new data on the link between pre- and postnatal exposure to the herbicide GLA and the onset of autism-like symptoms later in life. It also raises fundamental concerns about the ability of current safety testing to assess risks of pesticide exposure during critical developmental periods.  FULL TEXT

McDuffie et al., 2001

Helen H. McDuffie, Punam Pahwa, John R. McLaughlin, John J. Spinelli, Shirley Fincham, James A. Dosman, Diane Robson, Leo F. Skinnider and Norman W. Choi, “Non-Hodgkin’s Lymphoma and Specific Pesticide Exposures in Men: Cross-Canada Study of Pesticides and Health,” Cancer Epidemiology, Biomarkers, & Prevention, 2001, 10.

ABSTRACT:

Our objective in the study was to investigate the putative associations of specific pesticides with non-Hodgkin’s Lymphoma [NHL; International Classification of Diseases, version 9 (ICD-9) 200, 202]. We conducted a Canadian multicenter population-based incident, case (n = 517)-control (n = 1506) study among men in a diversity of occupations using an initial postal questionnaire followed by a telephone interview for those reporting pesticide exposure of 10 h/year or more, and a 15% random sample of the remainder. Adjusted odds ratios (ORs) were computed using conditional logistic regression stratified by the matching variables of age and province of residence, and subsequently adjusted for statistically significant medical variables (history of measles, mumps, cancer, allergy desensitization treatment, and a positive history of cancer in first-degree relatives). We found that among major chemical classes of herbicides, the risk of NHL was statistically significantly increased by exposure to phenoxyherbicides [OR, 1.38; 95% confidence interval (CI), 1.06–1.81] and to dicamba (OR, 1.88; 95% CI, 1.32–2.68). Exposure to carbamate (OR, 1.92; 95% CI, 1.22–3.04) and to organophosphorus insecticides (OR, 1.73; 95% CI, 1.27–2.36), amide fungicides, and the fumigant carbon tetrachloride (OR, 2.42; 95% CI, 1.19–5.14) statistically significantly increased risk. Among individual compounds, in multivariate analyses, the risk of NHL was statistically significantly increased by exposure to the herbicides 2,4-dichlorophenoxyacetic acid (2,4-D; OR, 1.32; 95% CI, 1.01–1.73), mecoprop (OR, 2.33; 95% CI, 1.58–3.44), and dicamba (OR, 1.68; 95% CI, 1.00–2.81); to the insecticides malathion (OR, 1.83; 95% CI, 1.31–2.55), 1,1,1-trichloro-2,2-bis (4-chlorophenyl) ethane (DDT), carbaryl (OR, 2.11; 95% CI, 1.21–3.69), aldrin, and lindane; and to the fungicides captan and sulfur compounds. In additional multivariate models, which included exposure to other major chemical classes or individual pesticides, personal antecedent cancer, a history of cancer among first-degree relatives, and exposure to mixtures containing dicamba (OR, 1.96; 95% CI, 1.40–2.75) or to mecoprop (OR, 2.22; 95% CI, 1.49–3.29) and to aldrin (OR, 3.42; 95% CI, 1.18–9.95) were significant independent predictors of an increased risk for NHL, whereas a personal history of measles and of allergy desensitization treatments lowered the risk. We concluded that NHL was associated with specific pesticides after adjustment for other independent predictors. FULL TEXT

Steckel, 2012

Larry Steckel, “Glyphosate-Resistant Weeds: Lessons Learned in Tennessee,” Presentation to the Iowa Soybean Association, On-Farm Network Conference, Ames, IA, February 16, 2012

SUMMARY:

Describes aggressive spread of glyphosate reisistant weeds and the importance of proactive management, including prevention and early detection and recommends herbicide protocols to control weeds. FULL TEXT

Shaw, 2017

William Shaw, PhD, “Elevated Urinary Glyphosate and Clostridia Metabolites With Altered Dopamine Metabolism in Triplets With Autistic Spectrum Disorder or Suspected Seizure Disorder: A Case Study,” Integrative Medicine, 2017, 16:1.

CONTEXT: Autism is a neurodevelopmental disorder for which a number of genetic, environmental, and nutritional causes have been proposed. Glyphosate is used widely as a crop desiccant and as an herbicide in fields of genetically modified foods that are glyphosate resistant. Several researchers have proposed that it may be a cause of autism, based on epidemiological data that correlates increased usage of glyphosate with an increased autism rate.

OBJECTIVE:  The current study was intended to determine if excessive glyphosate was present in the triplets and their parents and to evaluate biochemical findings for the family to determine the potential effects of its presence.

DESIGN: The author performed a case study with the cooperation of the parents and the attending physician.

SETTING: The study took place at The Great Plains Laboratory, Inc (Lenexa, KS, USA).

PARTICIPANTS: Participants were triplets, 2 male children and 1 female, and their parents. The 2 male children had autism, whereas the female had a possible seizure disorder. All 3 had elevated urinary glyphosate, and all of the triplets and their mother had elevated values of succinic acid or tiglylglycine, which are indicators of mitochondrial dysfunction.

INTERVENTION:
The participants received a diet of organic food only.

OUTCOME MEASURES:
The study performed organic acids, glyphosate, toxic chemicals and tiglylglycine, and creatinine testing of the participants’ urine.

RESULTS:
The 2 male triplets with autism had abnormalities on at least 1 organic acids test, including elevated phenolic compounds such as 4-cresol, 3-[3-hydroxyphenyl]-3-hydroxypropionic acid and 4-hydroxyphenylacetic acid, which have been previously associated with Clostridia bacteria and autism. The female, who was suspected of having a seizure disorder but not autism, did not have elevated phenolic compounds but did have a significantly elevated value of the metabolite tiglylglycine, a marker for mitochondrial dysfunction and/or mutations. One male triplet was retested postintervention and was found to have a markedly lower amount of glyphosate in his urine.

CONCLUSIONS:
The pattern of metabolites in the urine samples of the males with autism are consistent with a recent theory of autism that connects widespread glyphosate use with alteration of animal and human gastrointestinal flora. That theory is that the normally beneficial bacteria species that are sensitive to glyphosate are diminished and harmful bacteria species, such as Clostridia, that are insensitive to glyphosate, are increased following exposure to glyphosate. Excessive dopamine, caused by inhibition of dopamine-beta-hydroxylase by Clostridia metabolites, in turn, produces oxidative species that damage neuronal Krebs cycle enzymes, neuronal mitochondria, and neuronal structural elements such as the neurofibrils.  FULL TEXT

Kriebel et al., 2016

David Kriebel, ScD, Polly J. Hoppin, ScD, Molly M. Jacobs, MPH, Richard W. Clapp, DSc, “Environmental and Economic Strategies for Primary Prevention of Cancer in Early Life,” Pediatrics, 2016, 138:s1, DOI: 10.1542/peds.2015-4268

ABSTRACT:

This article summarizes the evidence for environmental toxic exposures contributing to cancers in early life, focusing on the most common cancer sites in this age group. It provides examples of widespread avoidable exposures to human carcinogens through air, water, and food and then describes recent examples of successful initiatives to reduce exposure to chemicals linked to these cancer sites, through government policy, industry initiatives, and consumer activism. State government initiatives to reduce toxic chemical exposures have made important gains; the Toxics Use Reduction Act of Massachusetts is now 25 years old and has been a major success story. There are a growing number of corporate initiatives to eliminate toxics, especially carcinogens, from the products they manufacture and sell. Another important opportunity for cancer prevention is provided by online databases that list chemicals, their toxicity, and lower-toxicity alternatives; these can be used by businesses, health care institutions, consumers, and workers to reduce exposures to chemicals of concern. The article concludes by inviting pediatricians and public health professionals to include elimination of carcinogen exposures in their work to promote primary prevention of cancer in early life. FULL TEXT