What You Need to Know About Heavy Metals

Brenna Leah Cashman BHSc., RNCP

Recent concerns about the lead content in many toys and the safety of plastic food packaging and containers have highlighted the dangers of environmental toxins.  For parents, the news can sometimes seem frightening and overwhelming.  Is everything in the home a potential source of harm?  Do we need to rid ourselves of every modern convenience?  Can we protect our children from all the toxins out there?

Parents may have difficulty finding clear answers to these questions.  As more research is done new information often reveals that products that seemed to be safe are not necessarily so.  Foods that were seen as healthy may actually contain dangerous levels of contaminants.  Product safety standards are not always enforced.  A changing environment and increased industrialization affects nearly everything we come in contact with.

Despite these factors though, most of us will go through life without seeing any direct adverse effects from environmental toxins.  So it can be tempting to ignore the news reports and assume that they are overly dramatic and not of any real concern.  Certainly, a healthy level of skepticism is good.  Not every report is accurate and not every product is as dangerous as it is portrayed.  The informed parent will realize, however, that there may be certain toxins that do indeed present a threat and that some foods and products should be limited or avoided entirely.

Heavy metals such as arsenic, lead, and mercury are minerals that are found naturally in the environment.  Until recently however, they were only found in minute amounts.  Technological advancements and increased industrialization have lead to our frequent exposure to these metals.  Toxic metals now pollute the water, soil and food chain.

The body is designed to filter out toxins and as such, absorption of these metals is usually fairly low.  But when the body is faced with increased exposure or reduced means of elimination, the metals can create problems by displacing related minerals that are needed for essential bodily functions.  For example, lead can replace calcium in the bones and tissues of the body, preventing calcium from carrying out its jobs.

So where are these metals found and how does one avoid them?

For some time now, lead has been recognized as one of the worst and most wide-spread pollutants.  Prior to the 1970s, lead was routinely used in paint and many older homes still contain leaded paint.  Older pipes may also contain lead, causing it to leach into the water.  Recent concerns about lead in children’s toys are especially significant as children are more sensitive to the effects of lead.  Lead can also be found in food, cosmetics, cigarettes, pottery, and some pesticides. 

It may be easy to overlook symptoms of lead toxicity, as they are fairly vague.  Headaches, constipation, vomiting, anemia, anorexia, fatigue and muscle pain are some of the early signs.  Other symptoms include irritability, poor coordination, memory loss, depression, hyperactivity and poor brain function.  Children with learning disorders may have a problem with lead intoxication.

The best way to reduce lead contamination is to limit exposure.  Diet also has an effect.  Calcium inhibits lead absorption and vitamin D increases body levels of calcium.  Vitamin C can help improve the elimination of lead and other toxic metals.  Iron, copper and zinc can also help to reduce lead contamination.

Another heavy metal that has recently gained more attention is mercury.  Common sources of mercury are dental fillings, cosmetics, fungicides and pesticides, and fish.  Families who are trying their best to eat well may be unknowingly consuming excessive quantities of mercury by eating too much of the wrong kind of fish.  Fish that contain high levels of mercury include swordfish, shark, and fresh tuna.  Children and pregnant women should be particularly careful to avoid these types of fish.

Symptoms of mercury toxicity depend on the type of mercury one has been exposed to.  A child’s developing nervous system is particularly sensitive to the effects of methyl mercury.  Excessive levels can lead to a decrease in I.Q., delays in walking and talking, blindness, lack of coordination and seizures.  In adults, too much mercury may lead to personality changes, memory loss, intellectual impairment, changes in vision and deafness.

While this may seem like enough reason to avoid fish altogether, it is important to remember that fish is good for you.  Fish like salmon, sole, tilapia, and whitefish are still good choices.  Canned light tuna is a better choice than fresh or even canned albacore tuna.  The site www.oceansalive.org contains excellent information about the toxicity of different kinds of fish and recommendations on safe fish consumption.  Fish has many health benefits and is an important source of essential fatty acids so it should be a regular component of the diet.

All of us will be exposed to heavy metals one way or another.  The important thing to remember is that our bodies can generally filter them out.  Our job is to limit exposure and do our best to avoid foods and products that may be heavily contaminated.  As more research is done it will hopefully become easier to recognize what we really need to avoid.  Increased safety and environmental standards should also help to provide our children with safer living conditions.  Until then, parents can help protect their families by following sensible safety precautions and staying up-to-date on the latest research.  A little extra awareness can go a long way to keeping your family healthy and well.