Cancer is an environmental disease. Prevention starts with everything that passes our lips – the air we breathe, the water (and everything else) that we drink, the food we eat, and the myriad other things that young children put in their mouths.
Substances that contribute to cancer are also absorbed through the skin, and again children are at particular risk with thinner skin and poorer abilities to detoxify and excrete toxicants. Read on to learn more about what to watch for, and how to prevent cancer.
TABLE OF CONTENTS
- Clear the indoor air!
- Be aware of outdoor air
- Mother Nature cleans air and water
- Scientific fine print: Air pollution
- Food preparation
- Food sensitivities/intolerances
- Scientific fine print: What is in your innards? Microbiota
- Bigger is not better
- Household cleaning
- Pest control
- Scientific fine print: Fluorinated compounds: Chemicals with unintended effects
— Prevent Cancer Now (@PreventCancerNw) January 18, 2016
We can live for days without drinking, weeks without eating, but only for minutes without breathing. Clean air is critical for health..
Clear the indoor air!
Minimize what is added to the air, such as:
- house dust and dirt tracked in from outdoors, as they can contain pollutants like lead from old paint, pesticides, anti-stain and anti-wrinkle chemicals (perfluorinated compounds), flame retardants and plastics ingredients;
- mould; and
- volatile organic chemicals (VOCs) from fragrances, air “fresheners,” paints and many other products (e.g. cleaners, fabric softeners, plastics, glues in furniture and cupboards, etc.).
Deal with indoor toxicants:
- Leave shoes at the door.
- Keep surfaces in good repair to minimize paint dust, and furniture in good repair to minimize dust from upholstery and padding.
- Clean frequently. Damp mop and dust. De-clutter.
- Use a central vacuum or one with a HEPA (High Efficiency Particle Arrester) filter.
- Eliminate moisture under sinks and in basements, and remove all mould.
- Use fans, air exchangers, and filters as needed; regularly clean or change your furnace filter.
- Renovation is a great time to make good choices for you and for the environment overall. Research thoroughly and choose wisely!
For resources on air quality at work, please go here.
Be aware of outdoor air
Outdoor air quality is reported in Canada, the US and Europe so you can choose to exercise outdoors during better air quality times. For active commuters and more sensitive individuals, a surgical mask is not sufficient to protect you from these pollutants; a better fitting mask with N95 protection is necessary for particles, and a carbon filter will remove chemicals. High quality dust masks are available from hardware stores, although the carbon filter may require shopping at a safety supply company.
A large proportion of air pollution comes from transportation. We can minimize the need for vehicles – and thus, air pollution – by walking, biking and using public transportation. Buying goods that are locally produced, from local merchants, also helps to reduce air pollution, and therefore cancer.
National minimum standards for air quality are set by the Canadian Council of Ministers of the Environment, but provincial or local standards are in some cases more protective. If you want to check on emissions from large facilities, these are reported through the National Pollutants Release Inventory.
Mother Nature cleans air and water
There are many reasons to protect, cherish, plant and tend to lots of trees. For example, loss of ash trees due to the emerald ash borer is leading to increased deaths from cardiovascular and lower respiratory causes.1 The same air quality factors and biological mechanisms that caused these deaths over the short term, also contribute to development of cancers over a longer timeframe.
Other natural features such as wetlands also offer many ecosystem and health benefits, including cleaner air and water. The bottom line for cities is to reduce asphalt so water infiltrates, replenishes ground water and supports a green landscape (and is consistent with “greener” transportation). Plant a diverse urban forest, and install green roofs.
Too much carbon dioxide and other greenhouse gases in the atmosphere is having devastating effects on our oceans, affecting food supplies, and increasing cancer-causing toxins such as mercury and cadmium in seafood. More broadly, climate change requires urgent action, and cancer features among the many health implications of global warming and associated natural disasters.
Scientific fine print: Air pollution
When breathed in, chemicals and very fine particles are absorbed directly into cells deep in the lungs and the bloodstream, and are circulated throughout the body. Unlike ingested substances, inhaled chemicals are not first passed through the liver for detoxification. They may also bypass the blood brain barrier, via the olfactory nerve pathway. Materials trapped in the upper airway may be blown out of the nose in mucus, but much is swallowed and can contribute to gastrointestinal and other cancers.
Air pollution is a known human carcinogen (Group 1), according to the International Agency for Cancer Research (IARC), with evidence for respiratory and bladder cancers (2). Diesel and gasoline engine exhaust are similarly recognized (3). The most common concerns are combustion byproducts such as small particles and their load of toxic metals and polyaromatic hydrocarbons (PAHs), as well as volatile organic compounds (VOCs), ozone, and “acid gases” such as sulphur and nitrogen oxides (SOx and NOx).
Ambient outdoor air pollution also affects reproductive and child health, causes lung, cardiovascular and other chronic diseases, and so is associated with high costs – for individuals, families and communities, and the health care system. The EU passed new measures for clean air in December 2013. Transportation is responsible for a large proportion of air pollution in urban areas, along with site-specific activities such as coal-fired power plants, industries, and household burning for heating and cooking.
High quality drinking water, as well as water for sanitation, is of utmost importance and is a human right.
Non-binding water quality guidelines are published by the Canadian Council of Ministers of the Environment (CCME) and may be applied by provincial and local governments. Canada’s standards are reported as lax and unenforceable compared with international best practices.
Municipal drinking water is usually chlorinated to kill germs, but reactions with organic content (such as rotting vegetation or animal wastes) in the water can create carcinogenic chemicals called chlorination byproducts (CBPs). These byproducts evaporate quickly, and a substantial dose can be inhaled during a hot shower, compared with drinking a glass of water. If you boil water or let it sit, the CBPs will off-gas. A glass jug of water left in the fridge will have lower levels of CBPs the next day.
Different concerns may come with private wells, Health departments generally process water samples for bacteria. You should check with your public health department for water testing recommendations for naturally occurring chemicals (e.g. arsenic) or environmental contaminants that may affect your water (e.g. from old industry or dump sites).
Lead from old pipes and fittings is still leaching into drinking water in too many homes. Only drink water from the cold water tap and let the water run until it is cold, especially first thing in the morning or after time away from home. Consider replacing plumbing, and work to have your municipality replace old lead water supply pipes. Drinks should never be stored in leaded glass (crystal) containers. Beside increased cancer risks, even low levels of lead harm children’s developing brains and organs. Lead is stored in bones, and continues to cause diverse harms at all ages.
A wide range of water filters are available. Many people use simple activated carbon filters, such as Brita pitchers and tap filters, which will remove some chlorination by-products and lead. Reverse osmosis and activated carbon may be needed to remove a broader range of chemicals. Do your research, and be vigilant with maintenance and filter replacement.
Bottled water is not regulated as stringently as tap water, since it is treated as a food product and normal water testing is not required. This leads many public health bodies to encourage drinking water from the tap. Besides, there is an enormous environmental footprint of the oil, manufacturing and transportation up front, plus disposal of billions of plastic bottles. Glass or stainless steel reusable drinking water containers are better options. Polycarbonate hard, clear plastic breaks down to release bisphenol-A, an endocrine disruptor. “Bisphenol-A free” substitutes (e.g. bisphenol-S) are also now recognized as endocrine disruptors. Soft plastics may leach other substances such as phthalate plasticizers (added to increase flexibility of the plastic). If you must use plastic, remember that the most readily recyclable plastic containers and bags are less likely to leach toxic chemicals (see plastics information).
The term “halogens” refers to a family of chemicals including fluorine, chlorine, bromine and iodine. They are commonly in salts, in the chemical forms fluoride, chloride, bromide and iodide.
Chloride is the predominant halogen in the body. It is in table salt (sodium chloride) and is essential to maintain bodily fluids and functions. Not to be confused, the chlorine chemicals in bleach and for water treatment are very reactive and very different from salt.
Iodine is an essential component of thyroid hormone. It may also be given to people to minimize absorption of radioactive iodine used in medical imaging or even following nuclear disasters, to prevent thyroid cancer. In efforts to minimize health effects of iodine deficiencies, it is added to flour and to table salt.
The lightest halogen, fluorine, is more contentious. Whether fluoride is truly an essential nutrient is not certain. Unlike iodide and chloride, health effects from insufficient fluoride have not been observed (6). Fluoride is common in our environment, water and diet, and at high enough levels it can interact with essential halogens, particularly iodide, indirectly impacting thyroid activity. Fluoride is chiefly bound in bone and teeth, and at low levels can contribute to their hardness. Higher levels cause weakening of bones and tooth structure, most obvious as mottling of teeth or dental fluorosis.
Fluoride containing additives sometimes used in drinking water in an attempt to prevent dental caries are byproducts of aluminum and fertilizer production. This occurs in a steadily decreasing number of jurisdictions, principally in North America. In fact, addition of fluoride to drinking water cannot be credited with decreases in dental caries, as improvements in oral hygiene in the modern era caused reductions in caries in areas both with and without fluoride added to drinking water (see Figure). The one and only study that carefully characterized early life exposure to fluoride in drinking water found increased risk of osteosarcoma in adolescent males who had been exposed to higher levels of fluoride in drinking water during their childhood (7).
Prevent Cancer Now opposes the addition of fluoride to drinking water, as it offers no discernible benefit and poses risk of cancer with exposures early in life. As well, other toxins may be contained in the industrial wastes that are used as fluoride-containing additives.
Image credit: Fluoride Action Network (http://fluoridealert.org/articles/50-reasons/who_data01)
Drinking water may naturally contain such carcinogens as arsenic, heavy metals or radioactive chemicals. Water may also be contaminated by previous and ongoing activities such as agriculture, mining for minerals or bitumen, hydraulic fracturing for petrochemicals (“fracking”), industrial activities, waste disposal or other land “uses.” Ground- and surface-water may contain fertilizers and pesticides, toxic minerals or petrochemicals, or a broad range of other industrial toxicants. Your public health department should know of local risks, but it is also good to know the history of the land before moving to a new location.
Be careful of what goes down the drain, because wastewater and downstream drinking water treatment plants are not designed to remove many modern chemicals, including pesticides, pharmaceuticals and ingredients in personal care products and cleaners.
Protect source water by:
- reducing wastes entering waterways from runoff, septic tanks or industries;
- keeping livestock out of streams; and
- maintaining vegetated shorelines and wetlands – nature’s filters.
This minimizes organic and nitrogen-containing materials entering the water treatment plant and naturally minimizes chlorination byproducts.
Increasing populations, intensive agriculture, industrial expansion, urban sprawl and climate change are all making clean drinking water supplies more precarious. Glaciers are melting, underground reservoirs are being depleted and becoming salty, and natural features that clean water and water sources are being impacted by development, invasive species and severe weather. Through the lens of water, it is clear that tackling broader environmental issues also impacts cancer prevention.
You are what you eat. We are all different, with individual nutritional needs depending upon age and stage of life, activities, life history, sensitivities and allergies. There is no single, universal, ideal diet.
Author Michael Pollon put it well, encouraging people to eat food, not too much, mostly plants, with others. He does not count highly processed products, or anything that can arrive through the car window, as food.
The World Cancer Research Fund (WCRF), and the affiliated American Institute for Cancer Research (AICR), continually update research databases on the links between diet/nutrition and cancer incidence, for particular cancers. They offer more detailed recommendations:
- As much as possible, choose a plant-based diet of fruits, vegetables, nuts, pulses (dried beans and lentils), grains and other seeds.
- Choose organic and locally grown foods as much as possible.
- Recognize that plant-based diets can readily and inexpensively provide high quality nutrition.
- Choose lean cuts of meat, organic and pasture fed versions if possible, minimizing red meat. Avoid processed meats, as carcinogens are formed from the preservatives. For example, higher risks of childhood leukemia were seen with intake of hot dogs, and bladder cancer with intake of bacon (8,9).
- Reduce or eliminate added salt, refined sugar, white flour and starch, and alcohol.
- Fish is a good source of protein and essential fatty acids, but can also contain mercury and persistent pollutants. The best choices are not obvious, but Sea Choice points out that for many reasons the healthiest options are also the most sustainable. Search for choices here. Other guidance is available here. Fishing guidelines based upon location, species and size are available for various jurisdictions such as Ontario.
No single food is a silver bullet, and the secret lies in a diverse diet of healthy, colourful foods. You can’t determine what toxins are in your food from the label, but organic production methods are likely to result in lower levels of contaminants such as pesticides and toxic metals.
Potential anti-cancer effects of natural hormones such as Vitamin D and melatonin, as well as compounds found in foods are the focus of much research. Whole foods are the best sources of nutrients, though depending on your exposures and risk level, commercial supplements may be beneficial. A large number of specialty foods and supplements are available off the shelf, but it is best to consult a knowledgeable, trained professional about personal concerns and choices. Medical research regarding some commonly used herbs and supplements such as Vitamin C, DHEA, CoEnzyme Q10, curcumin and others is summarized by Memorial Sloan Kettering and simpler information summaries are provided by the Mayo Clinic.
How you prepare your food may be as important as the food itself.
- For vegetables and fruit, raw is often a good choice, although light cooking to break down tough cell walls may make nutrients more available (e.g. carrots).
- It is possible to “juice” vegetables and fruits to increase nutrient availability, but you will miss out on their insoluble fibre.
- When overheated, proteins and starches can form cancer-causing chemicals, so low heat, slow cooking methods are safest. Brief steaming is great for vegetables.
- Non-toxic cookware is made of stainless steel, cast iron, or glass.
- Avoid non-stick coated pans – especially when over-heated, they can release perfluorinated compounds, that disrupt hormone actions.
- Never microwave food in plastic containers – always use glass. Glass containers are better than plastic for storage as well.
Some chemicals that can contribute to cancer dissolve in water. For example, grains such as rice accumulate arsenic (a known carcinogen) from the water and soil. Arsenic can be removed from rice by soaking and rinsing it, then boiling it in excess water and draining before serving. Although PCN does not recommend hotdogs, a major concern with them is nitrate, which also goes into the water with boiling and can be drained away. Unfortunately many toxicants do not dissolve in water, but it is also possible to trim and drain fats from cooked meats to reduce fat-soluble toxicants.
We all live in different circumstances. Cooking isn’t always easy with families to feed and limited time and money. It can help if you plan your meals in advance, and choose beans, lentils, nuts and so on, rather than meats as your main protein source. Stock up on fruits and vegetables when they are in season.
Family and communal meals are great opportunities to communicate and share, and are often nutritionally superior to snacks grabbed on the run.
Food allergies are commonly recognized, since acute reactions to such allergenic foods as peanuts can be life threatening. Intolerances are often chronic, with slower onset and resolution of symptoms, so are harder to recognize. Intolerances arise through different immune mechanisms as well as low enzyme production, leading to inability to digest substances such as lactose, malabsorption of nutrients, leaky gut and autoimmune reactions. Food intolerances sometimes come on slowly and have chronic effects, making it more difficult to identify offending exposures.
Gastrointestinal inflammation fueled by allergies, sensitivities and autoimmune reactions may result in higher risk of cancer. This is documented with undiagnosed celiac disease,10 where colorectal cancer risk falls after a year on a gluten-free diet, but may apply to other food sensitivities, which cannot be diagnosed with skin prick testing or detection of immune factors in the blood.
It is important to be aware of foods that do not “agree with you.” An elimination diet is a good strategy to identify food sensitivities, if symptoms improve then recur when the food is eaten again. As well as eliminating problematic foods, a rotation diet, eating from different food groups (i.e. different families of vegetables, fruits, and protein sources daily) may be helpful to reduce sensitivity reactions. Remember, eliminating foods means eliminating their nutrients, so take care to ensure balanced and complete nutrition. Advice from a naturopath or registered dietician can be of great help.
It is a surprise to many people that our bodies contain many times more microbes (mostly bacteria) than human cells. We rely upon this “microbiota” to digest our food, and to make some vitamins and important small molecules. Collectively, these organisms affect inflammation and permeability of the intestine, modulate our immune system and impact allergies, and can even affect our brains. At the undesirable end of the microbiota spectrum, some pathogens and parasites have harmful effects ranging from tooth decay, to various diseases including cancer. (See here for infectious agents known to cause cancer) Laboratory studies link shifts in the species in the microbiota with colon cancer in mice (11). A 2014 study linked household dogs with microbes in house dust, hence in the microbiota, and finally also with risk of allergies (12). A review describes how microbiota change with diet, and suggests that research is needed (13,14) to examine how eating pre-biotics (important bacterial foods such as complex carbohydrates and fibre) and probiotics (bacteria such as are found in yogurt and other live fermented foods) may affect cancer risks (15). Michael Pollon wrote a delightful, informative overview, “Some of my best friends are germs.”
Being over-sized correlates with increased risks of cancer.
In many studies, obesity and cancer go hand in hand. What is less clear is how much obesity itself is responsible, or whether obesity is just a marker for cancer-causing exposures. “Obesogens” are chemicals that affect metabolism (including development of diabetes) and satiety (feeling full). Many obesogens are endocrine (hormone) disruptors that are known to contribute to development of cancer. So, is the root of the cancer/obesity connection a straightforward link between fat and cancer? It is possible that chemicals such as phthalates, bisphenol-A, some pesticides and persistent pollutants, underlie both metabolic problems/being overweight (16), as well as cancer (17). In any case, the bottom line is that high fibre, largely plant-based, highly nutritious food choices and exercise (preferably with sweating) are keys for weight control and elimination of these toxicants (18).
Not only obesity, but undergoing exceptionally rapid growth during adolescence resulting in being tall (19) has been identified as an even stronger risk factor for cancer. This single study will doubtless spur further research.
Many of us use a variety of products to be clean and beautiful, and these are readily absorbed through the skin. Women may use twenty personal care products a day, while men may use ten. Many products contain chemicals we now know could contribute to cancer. It can be a complex puzzle to decipher chemical names and acronyms in fine print.
Top things to avoid would include:
- fragrance or parfum
- coal tar derivatives
- dark hair dyes (although some “greener” options may exist)
- the antibacterial ingredients triclosan and triclocarban
- formaldehyde-releasing preservatives (e.g. quaternium-15, dimethyl-dimethyl (DMDM) hydantoin, imidazolidinyl urea, diazolidinyl urea, sodium hydroxymethylglycinate, and 2-bromo-2-nitropropane-1,3-diol (bronopol))
There are, unfortunately, quite a few other ingredients of concern. Easy first steps are to switch to products without fragrance/parfum, or antibacterial chemicals (products are typically labelled as antibacterial). There is no evidence that antibacterial soaps are any better than plain soap to prevent infections in the community.
Mixtures of the thousands of un-labelled potential fragrance ingredients induce sensitivities and are otherwise toxic. Fragrances are often accompanied by endocrine disrupting phthalates to make the smell last longer. These phthalates are absorbed by the body and can be detected in urine.
Antibacterial chemicals may cause immune suppression (20), increased allergies/sensitization (21), decreased thyroid hormone (22), pollution of waterways (23), and may even promote resistant bacteria in fresh water and in the community.
The possibility of links between breast cancer and underarm products persists, as cancers are more common on the outer aspect of the breast. Aluminum (a common antiperspirant ingredient) was found in higher concentrations in nipple fluids from cancer versus control subjects. Endocrine disrupting phthalates in scented products also promote breast cancer (24). Armpit bacteria, the cause of underarm odour, can be reduced simply with frequent washing and shaving. Some manufacturers offer aluminum-free deodorant sticks. A baking soda and cornstarch mix can also reduce wetness and odour.
Remember, green-sounding product descriptions of “natural,” etc. are not backed by standards, except for the term “organic” along with reference to certification.
Some organizations that have delved into the complexities of personal care products include:
- The David Suzuki Foundation What’s Inside? That Counts
- Environmental Defence Just Beautiful and Taking Stock
- US Environmental Working Group buying guide Skin Deep Cosmetics Database
- The Campaign for Safe Cosmetics
Visit these websites to learn more about what to avoid, what to purchase, and ways to do without some products.
Some cosmetics contain toxic compounds. Health Canada established a Cosmetics Hotlist of restricted and prohibited chemicals, following unfortunate detections of toxins such as lead and mercury in cosmetics. It is important to report adverse reactions to cosmetics, as well as incidents with any consumer product including pesticides, drugs, foods, etc.
Keeping things simple is a healthy, thrifty strategy. You can even use food ingredients to whip up personal care products (the Queen of Green has some great ideas to start).
Many cleaning products contain diverse chemicals that may contribute to cancer, and should be avoided. Ingredients we should avoid in personal care products often find their way into cleaners too.
Shopping can be tricky because only the term “organic” has rules attached to it. Other terms such as “green” or “natural” are actually meaningless, so read the ingredients, if they are listed. Cleaner manufacturers are not compelled to list ingredients in Canada. Support those that do, and contact other manufacturers to ask for better labelling.
Household cleaning is an opportunity to save money and the environment, at the same time.
- You can accomplish most of your cleaning with vinegar or baking soda (don’t mix them together!) and water. If necessary, add soap, oxygen bleach and other food grade ingredients. For example, use cooking oil rather than a toxic solvent to remove pine gum.
- Avoid fragrances in cleaning products.
- Avoid air “fresheners,” automatically dispensed toilet chemicals, chlorine bleach, ammonia and organic solvents. If strong chemicals are necessary, protect yourself and others, seal off other parts of the home, and ensure good ventilation.
- For your clothes, skip the fabric softener. The raw ingredients have an unpleasant odour so these products require strong fragrance chemicals and phthalates to prolong the scent, or the addition of a chemical to deaden the sense of smell – a “masking agent.” “Dryer balls” can help to soften clothes and reduce static, and the balls last a long time.
- Look for drycleaners that do not use the solvent perchloroethylene (PERC). If you are stuck with this, remove the plastic cover and air your newly cleaned clothes outdoors.
Renovating can be a great opportunity to improve your indoor environment. Here are a few precautions to consider:
- If the home was built before 1990 check for lead (in paint and plumbing) and asbestos (in many places such as insulation in walls and around pipes, heat-resistant barriers, fabrics and gaskets, wallboard fill and patching compounds, textured walls and ceilings, shingles and floor tiles). Get professional help for testing and remediation, if needed.
- Use materials (e.g. flooring, paints, cabinets) that emit low amounts of volatile organic compounds (VOCs). Formaldehyde is a known carcinogen that emanates from glues in composite wood. Low VOC products and materials may be less toxic, and although there are no guarantees, they tend to be more durable.
- Furnishings with materials such as metal, glass, organic cotton and wool, and solid wood don’t require flame retardants. Flame retardants, as well as stain repellents, rub off, are absorbed by skin and inhaled in dust, and may cause rashes and disrupt the endocrine system.
- Use good work practices. Seal off and isolate renovation areas, keep things clean, and clean the air ductwork afterwards.
- If you are installing an air purifier, get one with a filter and activated carbon – not an electrostatic one that might generate the irritant ozone. The Lung Association offers further advice.
- Carpets tend to off-gas (emit VOCs over the long term), trap dust and harbour moulds, so if you have a choice, it is better to use ceramic or hardwood.
Research by Canada’s National Research Council measured air pollution from renovation materials in an office. The choice of renovation materials made a difference of 100-fold in the indoor levels of volatile organic compounds, even after a month.
Strategies for less toxic pest control include good maintenance to remove pest “habitat” such as rotting wood, damp areas, and crumbs of food. For any remaining pests use enclosed baits (borax is a low-risk option for ants), and traps.
Plastics are everywhere, in our homes and products, and even in the ocean.
Bisphenol-A makes up polycarbonate (PC), a hard, clear, tough plastic that is popular for water bottles and linings of cans. It also mimics the hormone estrogen so could promote cancer. When this material was banned from baby bottles, many manufacturers offered “BPA-free” products containing BPS, that we now learn is at least as powerful as BPA at disrupting the endocrine system. Unfortunately substitutions of one ingredient for another in plastics may amount to going from the “devil you know” to the “devil you don’t know.” With countless potential ingredients, the combinations are virtually endless. Glass is a great, non-toxic option, and plastics numbered 1, 2, 4 or 5 are less likely to contain endocrine disrupting chemicals.
One objective of “green chemistry” is to provide less hazardous, as well as more sustainable options for plastics. Plastics that are more readily recycled require fewer additives, and may be better options for both health and sustainability reasons (see “Plastics decoded”). Certain plastics can (and should) be manufactured of a composition and purity that they do not cause health effects, but tests of a large number of diverse samples found estrogenic chemicals leached from all plastics tested (25). Recycled products (particularly dark items) may include toxic additives from previous incarnations, such as flame retardants from recycled electronics waste; these have sometimes been found in cups and utensils.
From a broader perspective, plastics are made with petrochemicals (even bio-plastics require fuels to plant, grow and harvest raw materials), so are of concern for global warming. It is essential to reduce plastics and plastic waste in packaging and disposable goods, to recycle, and to avoid including plastic in compost.
Plastic microbeads in cosmetics and facial scrubs are not stopped by sewage treatment plants, and are contaminating lakes and oceans. The billions of bags and plastic detritus in the ocean slowly crumble into smaller pieces that bind cancer-causing contaminants. These polluted plastic bits are then eaten by marine life, where they may block digestion, give the organism a dose of persistent toxicants, and may even kill the creature outright. This high toxicant dose essentially kick-starts the well known process of bioaccumulation up the food chain lead to recommended restrictions on fish intake. As toxicants reach higher levels in larger species, they may be at higher levels than they would be otherwise and thus exert stronger toxic effects.
Municipal compost in Canada contains significant, easily visible plastic shreds. Although we don’t know as much about what happens to plastics in compost, it is reasonable to expect similarities – that soil organisms may be adversely affected, and food may also be more highly contaminated via interactions of plastics in compost. Research is needed in this area. In the meantime, only put natural, readily biodegradable materials into compost.
- Choose numbers 1, 2, 4 and 5, and ask for others to be substituted.
- Don’t heat food in plastic containers.
- Work to reduce packaging and to eliminate PVC and PS from packaging.
Polyethylene terephthalate (PETE) is a clear, hard plastic that is often in disposable food and drink containers. PETE is easy to recycle and is usually accepted by Canadian municipal recycling programs. Look for products containing recycled PETE such as containers, furniture, carpet, and polar fleece fabric.
High density polyethylene (HDPE) is a hard plastic that is not transparent, found in containers and bottles (e.g. for shampoo or yogurt). HDPE is easy to recycle and is usually accepted by recycling programs in Canada. Look for products with recycled HDPE such as pens, containers, bottles for non-food uses, drainage pipe and fencing.
Polyvinyl chloride (PVC) is used in a wide range of products, from bottles, medical devices, shower curtains and toys, to clear packaging.
- PVC is the most toxic plastic to produce;
- the vinyl chloride vapours it emits may cause cancer (this is the smell of a new shower curtain);
- it requires the largest number and quantities of additives such as hormone-disrupting phthalates to soften it and heavy metals to stabilize it;
- it is very difficult to recycle;
- burning PVC produces dioxins; and
- PVC lasts a very long time if you throw it away.
Look for PVC-free products, ask stores and manufacturers to use better materials, and ask governments to ban, reduce and substitute PVC wherever possible.
Low density polyethylene (LDPE) is a soft, flexible plastic that is found in a variety of plastic bags. It is a low risk plastic. LDPE can be recycled, and is being added to Canada’s municipal recycling programs. There are no health concerns connected to LDPE.
Polypropylene (PP) is found in food containers, medicine bottles and many plastic items such as toys. It is a low risk plastic. PP is often, but not always accepted by municipal recycling programs. Look for recycled PP in miscellaneous plastic products.
Polystyrene (PS), commonly known as Styrofoam, may be found in disposable cups, meat trays and take-out food containers. PS contains styrene, a known carcinogen. PS is not usually accepted by municipal recycling programs, although it is sometimes recycled to make insulation. Look for PS-free products, and ask stores and manufacturers to use better materials. Don’t put hot materials into PS containers, including beverages.
Number 7, “other plastics” is often polycarbonate (PC). This hard, clear plastic is most often in containers such as for water. PC and some substitutes leach chemicals that interfere with hormones. “Other plastics” are usually not accepted in municipal recycling programs.
Fluoro-organic chemicals (containing a large number of fluorine atoms) are widespread, and are commonly added to materials and furniture. They are very persistent, building up in the environment and people. These chemicals can disrupt endocrine, neurological and immune systems, potentially causing cancer. Fluorinated chemicals are most famously in Teflon® for cookware, and are also in stain- and water-repellant as well as anti-wrinkle treatments for cloth. One of these chemicals, PFOA (perfluorooctanoic acid), is restricted under the Stockholm Convention.
Fluorinated compounds may be found in many products, including:
- non-stick cookware;
- clothing (including popular water-proof breathable fabrics). Purchase untreated clothing, or research the latest ingredients carefully;
- furniture and floor coverings. Skip the optional stain repellant treatment when your furniture and rugs are cleaned;
- food packaging, such as for microwave popcorn and prepared meals;
- high performance ski waxes; and
- various products used on surfaces such as some windshield washer fluids, greases, paints, polishes, cosmetics, nail polish, and pesticide formulations.
In many cases the label touts the fluorinated chemicals as a higher-cost feature, so beware (and be thrifty!).
The first flame retardant synthetic chemicals were polychlorinated biphenyls (PCBs). These are now targeted for elimination internationally under the Stockholm Convention, but persist in the environment and in us. PCBs were followed by similar flame retardant chemicals, with bromine instead of chlorine. The polybrominated flame retardants unfortunately exhibit similar undesirable features, and while PCBs are known human carcinogens, IARC (International Agency for Research on Cancer) classified the newer brominated biphenyls as probable human carcinogens (26).
According to an investigative exposé in the Chicago Tribune, these chemicals were advanced by the tobacco industry as a solution to fires from dropped cigarettes. The chemicals are not particularly effective, and pose many hazards, particularly to firefighters.
Flame retardants were also required in infants’ clothing, although not for natural fibres that do not flare up. The chemicals are particularly easily absorbed through infants’ skin and lungs, and early life exposures may have life-long consequences. Look for cotton clothing with the label “Wear snug-fitting. Not flame resistant.”
Substitutes for current flame retardant chemicals may also pose health and environmental risks, so use of products without these additives is the best choice.
The workplace may be linked to increased risks of cancers, although many barriers may hinder addressing these issues. Preventive steps include substituting chemicals with least-toxic options, good engineering and maintenance to minimize emissions and leaks, adequate ventilation and personal protection, and education regarding workplace exposures and safer work practices.
All workers have the right to know to what they are being exposed, and to be provided with Workplace Hazardous Materials Information Sheets. Workers are encouraged to maintain a diary of workplace exposures, should any health issues occur in the future.
If you are working with hazardous materials, it is best to shower and change at work. “Take-home” exposures, in both vehicles and the home, can affect the entire family. Take care, and launder work clothes separately.
Strong Occupational Health and Safety Committees are key to recognizing and mitigating risks in workplaces.
Depending upon the workplace, examples of occupational exposures that may contribute to cancer include engine exhaust, various petrochemicals in the energy and chemicals industries, plastics components, some drugs and pesticides, radon and minerals in mining and metals processing, ash from burning coal and trash, and solvents. Many of these chemicals are endocrine disruptors, acting at very low exposure levels.
Industrial areas may affect cancer incidence, as was seen in areas of the Great Lakes associated with industrial activities (27), and recently observed downwind of Alberta bitumen processing facilities (28).
Shift work and trouble sleeping have also been linked to cancer, including of the breast (30) and prostate (31). This may result from low levels of melatonin, the “sleep hormone,” that also acts as an anti-oxidant. Melatonin supplementation is an area of active research, to improve sleep and mood, as well as prevent cancer (31).
Although carcinogenicity of many substances have been assessed in groups of workers, cancer risks can be complex, especially for mixtures or multiple exposures. For instance, a Canadian study found that increased risks of breast cancer associated with working in manufacturing were further exacerbated by previous farming and associated pesticides (32).
Click here for links to resources on occupational health and cancer.
— Prevent Cancer Now (@PreventCancerNw) January 8, 2016
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