Pesticides and Your Health — A Family Physician's Perspective

British Columbia and Nova Scotia are considering potential bans on lawn and garden pesticides. "Cosmetic" pesticides are already prohibited in Quebec and Ontario and new restrictions will be in effect this summer in New Brunswick and PEI, too.

Ultimately, the controversy surrounding pesticide use comes down to health — if these chemicals are harmful, they should be banned; if they are safe they can be used widely and freely without restriction. However, determining whether a chemical is harmful or not is not always easy or straightforward. The studies that can be done on pesticides are mostly population studies looking at whether people with increased exposure to multiple pesticides develop illnesses more than the average. The studies have some limitations, and cannot always draw unequivocal conclusions.

In 2004, Dr. Vakil co-authored a scientific review of published research examining the human health effects of pesticides for the Ontario College of Family Physicians. They searched commonly used medical databases and reviewed 265 studies on cancer, and neurological, dermatological, reproductive and immunological/genotoxic disorders that met our strict criteria for methodological quality.

Unfortunately most studies examined occupational exposure of only adult males, with a paucity of studies looking at women and children. Yet the few studies available suggested that pregnant women and children are particularly vulnerable. Dr. Vakil and her colleagues concluded that there was enough evidence of the harmful effects of these chemicals that doctors should advise their patients to avoid all possible exposure. Here's a look at what they found.

There were 104 studies looking at a number of different cancers. Most of these found a link between pesticide exposure and cancer, many of them reaching statistical significance (meaning the associations found were unlikely to be by chance). Increases in Non-Hodgkin lymphoma were found in farmers, pesticide production workers and golf course superintendents, and one study in children found elevated rates of the cancer when pesticides were used in the home and when parents had occupational exposure.

One study found an increase in childhood leukemia with home exposure and prenatal exposure to pesticides. In this study children with a "poor metabolizer" genetic mutation increased the risk of leukemia with exposure to pesticides, indicating a possible genetic predisposition. Other studies showed that exposure to pesticides in early childhood, prenatally and even pre-conception may increase risk of leukemia.

All the studies on brain and kidney cancer showed increased risk with pesticide exposure even in the children of exposed workers. One study found a decreased risk of breast cancer in farming women, though risk was elevated for those women who reported being in the field during or shortly after pesticide application, as well as for those who reported not using protective clothing.

All eight papers on prostate cancer showed elevated incidence in workers who were exposed to pesticides, with one showing higher rates in exposed workers with a family history of prostate cancer.

Skin is the primary route of exposure to pesticides for workers. A few high-quality studies showed increases in rashes in agricultural labourers and pet groomers.

Thirty-nine of 41 studies on neurotoxicity found an association between pesticide exposure and one or more neurologic abnormalities such as mild cognitive dysfunction, neurobehavioural changes, depression, and even suicide. Only two studies examined children, finding significant neurodevelopmental effects in preschool children with pervasive agricultural exposure in Mexico. Previous pesticide poisonings were found to be related to impaired neurobehavioural function, and 15 out of 26 studies found associations between pesticide exposure and Parkinson's disease.

Fifteen studies from nine countries found increases in birth defects (limb, urogenital, central nervous system, orofacial and heart anomalies) with pesticide exposure of the mother. Results of the studies on fertility were mixed but several did find reduced fertility, sperm abnormalities and erectile dysfunction with increased pesticide exposure. Some studies showed that preconception and prenatal exposure to pesticides may increase low birth weight, prematurity, stillbirth, miscarriage and neonatal death.

Chromosome aberrations (genetic damage to cells which could present as miscarriage, birth defects, sperm abnormalities or cancer) were found in 11 of 14 studies, though other factors such as smoking, radiation, diet and alcohol consumption were not always accounted for.

Overall, this review on the health effects of pesticides provides clear evidence that pesticide exposure increases risk to human health. As a doctor, it's my role as health advocate to advise my patients to reduce exposure to all pesticides whenever possible, and to promote the passage of legislation banning non-essential pesticide use and sale. This would protect especially vulnerable populations such as women and men considering pregnancy, pregnant women, infants and children.

Cathy Vakil is a family doctor at the Department of Family Medicine at Queen's University in Kingston, Ontario and has an interest in health and the environment. She is on the Environmental Health Committee of the Ontario College of Family Physicians and the Board of Directors of Canadian Association of Physicians for the Environment (CAPE). Her interests include the health effects of pesticides, urban sprawl, climate change, air pollution and nuclear energy.

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Source: DavidSuzuki.org

Environmental Links to Cancer & Environmental Human Rights

The U.S. EPA classifies chemicals into five categories -- A through E -- to identify their carcinogenicity to humans, with A being known carcinogens, B the probable human carcinogens, C the possible, D the unknown due to lack of data, and E the noncarcinogens. "The fact that numerous chemicals with long-standing membership in Groups A through C are still allowed to be manufactured, sold, released, dumped, imported, exported, or otherwise used comes as a surprise to many knowledgeable people," states ecologist and cancer survivor Sandra Steingraber, an internationally recognized expert on the environmental links to cancer.

There are 60 possible carcinogens in the air we breath.

There are 66 possible carcinogens in the food we eat.

There are 40 possible carcinogens in the water we drink.

Its not just the dose that makes the poison and its not just the timing that makes the poison, its who you are that makes the poison.

The disconnect between what the scientific community know about carcinogens and what cancer patients are told is huge.

"We should become carcinogen abolitionists. These chemicals simply need to be phased out." says Steingraber. "When carcinogens are released into the environment some number of vulnerable persons are consigned to death. I don't have time to put a happy face on cancer. Cancer is a serial killer."

"An environmental human rights movement is the vision under which I labor and which may if we all work together in concert become a self fulfilling prophesy. May it be so."

Sandra Steingraber explores the links between human rights and the environment, with a focus on chemical contamination. She takes a personal and scientific look at these issues and offers insights into how we can protect our environment and ourselves.

A Bridge to Somewhere - Responding to the President's Cancer Panel Report (Part 3)

Dr. Sandra Steingraber

Authority on environmental links to health

Posted: July 7, 2010

The Panel was particularly concerned to find that the true burden of environmentally induced cancer has been grossly underestimated. The President's Cancer Panel urges President Obama "to use the power of [his] office to remove the carcinogens and other toxins from our food, water, and air that needlessly increase health care costs, cripple our Nation's productivity, and devastate American lives." reports Steingraber. Visit Livingdownstream.com for more information on cancer survivor Sandra Steingraber's book and documentary.

HOW MUCH EVIDENCE DO YOU WANT? 

CHEMICAL EXPOSURE & CANCER

Environmental Links to Cancer

Interview with Dr. Sandra Steingraber, biologist, poet, and survivor of cancer in her twenties, brings all three perspectives to bear on the most important health and human rights issue of our time: the growing body of evidence linking cancer to environmental contamination. "Living Downstream" (book and documentary) is a scientist's personal investigation of cancer and the environment.

10:00 Pesticides don't just stay on the plants they evaporate and drift into the air, they fall as "rain", they're found in snowflakes, in fog, in wind, in clouds and backyard swimming pools. So why do so many farmers feel that they still have to use pesticides? And do they not know how persistent they are in the environment.

Dr. Sandra Steingraber's documentary Living Downstream is now available for theatrical and festival screenings. Fifteen new screenings have been added.

Preview

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Posted by Olga Krywyj

Australian Government Bans Toxic Pesticide 'Endosulfan'

Reversing previous rulings that claimed that the toxic pesticide endosulfan was “safe,” the Australian Pesticides and Veterinary Medicines Authority (APVMA) announced its decision Tuesday to finally cancel the registration of the highly hazardous chemical. Recent assessments by the Australian government’s Department of Sustainability, Environment, Water, Population and Communities (DSEWPC) concluded that the prolonged use of endosulfan is likely to lead to adverse environmental effects via spray drift and run-off, and that these long-term risks could not be mitigated merely through use restrictions or label changes. Australia joins over 60 countries, including to the U.S. to have banned endosulfan.

 

Endosulfan is an organochlorine insecticide that was first registered for use in the U.S. in the 1950s. It is an endocrine disruptor and exposure in male children may delay sexual maturity and interfere with sex hormone synthesis. Endosulfan also decreases semen quality, sperm count, spermatogonial cells, and sperm morphology, and contributes to other defects in male sex hormones. It is volatile, persistent, and has a high potential to bio-accumulate in aquatic and terrestrial organisms. Two-headed bass, for example, were found in the Noosa River resulting from surrounding pesticide drift from neighboring farms in Queensland, Australia. The pesticides, endosulfan and carbendazim, were implicated in the contamination of the river, which has yielded thousands of chronically deformed fish.

In December 2009, the Stockholm Convention Persistent Organic Pollutants Review Committee (POPRC) recommended that urgent “global action” was needed to address health and environmental impacts of the toxic pesticide. Scientific experts at the POPRC concluded that endosulfan is likely to cause significant adverse human health and environmental effects as a result of the chemical’s medium- and long-range transport on a global scale and subsequent accumulation in nearly all environmental media.

In June, 2010, the U.S. Environmental Protection Agency (EPA) announced that it would take action to end all uses of the insecticide endosulfan, deciding that new data presented to the agency in response to its 2002 Reregistration Eligibility Decision (RED), which shows that risks faced by workers are greater than previously known. In completing revised assessments, EPA concluded that endosulfan’s significant risks to wildlife and agricultural workers outweigh its limited benefits to growers and consumers. EPA also found that there are risks above the agency’s level of concern to aquatic and terrestrial wildlife, as well as to birds and mammals that consume aquatic prey which have ingested endosulfan.

EPA’s decision followed a lawsuit that was filed on behalf of environmental and farmworker groups, including Beyond Pesticides, on July 24, 2008. The suit cited a glaring omission in the EPA’s decision in its failure to consider risks to children: a 2007 study found that children exposed to endosulfan in the first trimester of pregnancy had a significantly greater risk for developing autism spectrum disorders. It also poses risks to school children in agricultural communities where it has been detected at unsafe levels in the air. In addition, endosulfan has been found in food supplies, drinking water, and in the tissues and breast milk of pregnant mothers.

According to APVMA, endosulfan will be discussed in October 2010 at a scientific advisory meeting of the Stockholm Convention on Persistent Organic Pollutants. This meeting will determine whether to recommend to the Conference of the Parties meeting in April 2011 to globally ban or restrict endosulfan. For more information on APVMA’s decision, see the agency’s Chemicals in the News page.

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Source: BeyondPesticides.org