Pesticides are used to control pests that can affect our health, safety or food supply. This use of pesticides is called non-cosmetic because it’s needed for public health and safety.
Pesticides are also used to make lawns, gardens and other green spaces look better. We call this use cosmetic because it’s not needed for health and safety.
Studies show that there may be a connection between pesticides and cancer in adults and children. That’s why you should reduce – and even eliminate – exposure to pesticides where possible. Our view about pesticides depends on what they are being used for. We discourage the cosmetic use of pesticides.
How you are exposed to pesticides
People can be exposed to pesticides at home or in the community in several ways:
- through the skin – absorption; passing into the body through the skin
- breathing into the lungs – inhalation
- swallowing – by eating what remains on vegetables and fruit, drinking contaminated water or touching contaminated hands to mouth
In your home
- pesticides used outdoors on lawns and gardens
- insect repellents – for example, for mosquitoes
- pesticides used indoors – for example, for ants, termites and cockroaches
- pesticides carried into the home from outdoors – for example, people working with pesticides who bring what remains on their clothing into the home
In your community
- pesticides carried in the air, water or soil contaminated by a nearby treated area – for example, drift from a farm or a neighbour’s lawn
- public health and safety use – for example, community spraying to control mosquitoes
- pesticides used in parks, recreational areas and other community settings
In your diet
- small amounts of pesticides on your vegetables and fruit left behind from growing, storage or transport
- drinking water contaminated by pesticides – for example, because of drift from a treated area
At your job
- pesticides used to protect growing crops, stored crops and livestock from damage on farms
- pesticides used to preserve foods for transport
- pesticides used on green spaces for recreation or sports – for example, on golf courses
- making or transporting pesticides
Pesticides and children
Children are at risk of being exposed to higher levels of pesticides than adults because:
- Some activities increase their exposure – such as crawling and playing in grass or gardens treated with pesticides or putting contaminated objects in their mouth.
- Pesticides can be absorbed through their skin more easily.
- They take in more air, water and food relative to their body weight compared to adults, which increases their total exposure.
Pesticide exposure may do more harm to children because their bodies are still developing and may not be able to deal with these substances.
Children can also be exposed to potentially harmful pesticides through their parents. For example, there is evidence that children whose parents work with pesticides are at increased risk of exposure to pesticides in the home. Another possible type of exposure is prenatal (before birth). Some studies suggest that the timing of exposure, such as prenatal exposure to pesticides may be important, but more research is needed to know how this may affect cancer risk in children.
Pesticides and cancer
The International Agency for Research on Cancer (IARC), the US Environmental Protection Agency and the National Toxicology Program classify pesticides according to their link with cancer. Find out more about how cancer-causing substances are classified.
Research to date does not show a definite link between pesticides and human cancer, but it does suggest an increasingly likely connection with cancers such as non-Hodgkin lymphoma (especially among farmers), multiple myeloma, and prostate, kidney and lung cancers. Studies on pesticides and childhood cancer show a possible connection with leukemia, brain tumours and non-Hodgkin lymphoma. The possible link between childhood brain cancer and parents’ exposure to pesticides at work was studied, but no link was found.
Farmers exposed to higher levels of pesticides
Studies were done with people who apply pesticides on farms to find out how many of these people get cancer and how many die from it. The results suggest this group may have a slightly higher risk than the average person of getting Hodgkin lymphoma, non-Hodgkin lymphoma, leukemia, multiple myeloma, soft tissue sarcoma and cancers of the prostate and brain.
For example, one study from the US Agricultural Health Study looked at people who apply pesticides. They found that more of these workers got prostate cancer compared with the average person. Also, a study of people who are exposed to pesticides at work, such as farmers and farm workers, suggested there may be a higher risk of myeloid leukemias in these workers. A study of migrant and seasonal farm workers found a higher than expected number of stomach cancer deaths.
More research needed
Current pesticide research doesn’t give us all of the information we need:
- There is only a small amount of research about exposure to pesticides in Canada – information is often from other countries that may have different exposure patterns and types of pesticides.
- Getting accurate information about exposure and health outcomes makes it hard to study the link between pesticides and cancer.
- Changes over time in the types of pesticides available and in their use can make it hard to understand the health risks of current products.
Tips to reduce your exposure
Pesticides spraying
- Stay indoors with your family and pets if a neighbour or someone else is using pesticides near your home. Keep your windows and outside doors closed.
- Ask your neighbour to tell you if pesticides will be sprayed on their lawn. Keep your family – especially your children and pets – away for at least 48 hours from those areas.
- Look out for signs posted on green spaces that show they were recently sprayed with pesticides and don’t walk or play in these areas.
If you live, work or play near farming areas where pesticides are used:
- Wait at least 48 hours before going into areas that have been sprayed.
- Ask your community to make sure signs are posted in sprayed areas.
- Stay indoors when pesticides are being applied and keep windows and outside doors closed.
Lawn and garden
Exposure to pesticides should be reduced to the lowest possible level. If pest control is needed for your lawn or garden, try to use safer options. The Canadian Cancer Society recommends the following alternatives:
- Dig out weeds at their roots.
- Keep lawns watered enough but not over-watered – 2 cm of water (less than 1") should be enough. Put a container on your grass when you water to help you measure.
- Never cut more than one-third of the height off your grass. If you do, it may leave your lawn open to weeds and diseases.
- Cut your grass shorter in the spring and then let it grow longer through the summer – this will help make sure strong roots develop.
- Aerate your lawn to allow moisture and nutrients to reach the roots of the grass.
- Rake your lawn with a heavy rake if needed to remove dead grass and roots that can build up above the soil surface.
Pesticide residues on vegetables and fruit
- Pesticides are used during the growing season or to store and transport fresh vegetables and fruit. Sometimes traces of pesticides (residues) are left behind. You can reduce and often eliminate pesticide residues on the fresh vegetables and fruit you eat if you:
- Wash all fresh vegetables and fruit thoroughly with lots of running water.
- Use a small scrub brush to clean the skin of vegetables and fruit if the skin will be eaten – for example, apples, potatoes and cucumbers.
- Peel off the outer skin of vegetables and fruit and trim the outer leaves of leafy vegetables, and then wash thoroughly.
Protecting yourself and others at work
- Carefully read the product information about pesticides and follow the directions on the label.
- Reduce the amount of pesticides used.
- Reduce drift and environmental contamination. For example, add a buffer zone – leave a strip of land without pesticides next to a sprayed area. Spray pesticides on days with no wind when the temperature is below 25 degrees Celsius.
- Do not use pesticides around children or pets.
- Follow work health and safety requirements in your province – for example, when you can return to an area treated with pesticides.
- Wear protective equipment (for example, gloves and masks) as recommended on the pesticides label, and remove contact lenses before spraying.
- Don’t wear clothing at home that was used while working with pesticides – clothing worn at work should be washed separately and after each use.
- Don’t smoke, drink or eat when handling pesticides. Do not rub your eyes or touch your mouth while working with or after using pesticides. Wash your hands immediately after using pesticides.
- Never store pesticides near food or drinks.
- Never move pesticides into another container from the original one for storage. This will stop you or someone else from mistakenly misusing them. Also, do not throw out the safety instructions from the original label.
- Get rid of pesticide containers by following the instructions on the label. Contact the city or town office in your area about getting rid of unused pesticides.
- Store pesticides out of children’s reach.
- Post signs warning people that an area will be treated with pesticides.
Suggested links for more information about pesticides