Arsenic
Arsenic is common in the world. It's kind of just around, but it is also found in water, food, and pressure treated wood. It can get into water sources from naturally being found in soil. It can get into food from both the soil and the water applied to the crops as they grow. It is important to limit how often we come into contact with arsenic because, in large enough concentrations, or small, repeated doses over time, arsenic is poisonous.
One of the most common sources of arsenic for the general public, and especially people with a gluten intolerance and young children, is rice. Often young children and those avoiding gluten eat more rice, or products made with rice, than the average individual. While eating rice even a few times a week isn't something to worry about, eating large amounts of rice (like for multiple meals a day) can lead to higher arsenic levels. Trying a variety of different grains, like quinoa, oats, farro, and amaranth is a great way to limit the amount of arsenic coming from rice in your diet. Apple seeds are also known to have higher levels of arsenic. We recommend you just don't eat those (they don't taste very good anyway), but the rest of the apple is perfectly safe.
In terms of pressure-treated wood, if you have furniture or a deck made of pressure-treated wood, we recommend sealing it on a regular basis to keep the wood from releasing arsenic as you come into contact with it. While arsenic-treated wood for residential use was phased out in 2004, this is still important to think about if you have older outside furniture. Also, never use pressure-treated wood if you are building a fire. If you are touching the wood, be sure to wash your hands thoroughly when you are finished.
Finally, if you get your water from a well, test the water often for arsenic levels, and if needed, use bottled water or a filter that removes arsenic.
Mercury
This is more well known, but mercury can have some pretty serious health effects as a neurotoxin, especially for developing babies and children. There are a few forms of mercury (elemental, organic, and inorganic), all of which can cause problems when they get introduced to human systems. The most common ways people are exposed to mercury are through accidentally being exposed to it in broken products that contain mercury, through dust as coal is burned for energy and heat, and, most commonly, through eating fish and shellfish. The bigger the fish, the more likely it is to have higher levels of mercury because it often starts in small fish and as bigger fish eat the smaller fish the bigger fish collect larger amounts of mercury. This is true for humans, too. As you eat fish that contain mercury, that mercury builds up in your body over time. This is called bioaccumulation, meaning that little amounts add up to bigger amounts in your body over time. The best way to avoid mercury is to check guides for the best fish choices and to carefully dispose of batteries, very old thermometers, and CFL light bulbs, which also may contain mercury.
Lead
There's been some news about this one lately, so you've probably got some idea how ingesting lead can be not so great. Lead can cause reproductive problems, cardiovascular disease, learning disabilities, and diminished kidney function. Because of this, and its well documented dangers for children, the CDC has determined that there is no safe level of lead, meaning you always want to avoid it.
Lead had many common uses like in old paint and pipes, which is why we still have to worry about finding it in homes even though it's not allowed to be used in those products any more. A long time ago it was also added to gasoline for cars, so it has ended up as pollution and settled in the soil across the country. These are only some of the uses. It can also be found in artificial turf, cosmetics, and pottery glaze. We have a whole article on some easy way to avoid it in your home, but the three easiest tips are to always use cold water when cooking or drinking, wash your hands and your kids hands after playing outside in the dirt, and get a doormat to wipe your shoes on as you walk in the house, or better yet, have a no shoes in the house rule. All of these things can dramatically lower the amount of lead you come into contact with on a regular basis, and take little to no effort to change.
Cadmium
Cadmium, like everything else on this list, occurs naturally in the world. People most commonly come in contact with it through the food that we eat, or through cigarette smoke. Although, it is also found in some paint, rechargeable batteries, and in children's jewelry.
Cadmium ends up in food because it is absorbed by plants as they grow. This isn't a large concern for people in the US because cadmium levels are relatively low here, but in other countries, like Japan, this is a bigger concern. The biggest concern in the US is for people who smoke because tobacco plants are very good at absorbing cadmium, and the cadmium is transferred to the smoke as the cigarette burns. Which is just another reason to quit smoking.
There is also some worry for people who work in mines or with paints or soldering equipment. In those cases, the workers have a higher chance of inhaling cadmium, which can lead to kidney problems.
Cadmium has different health effects depending on how a person is exposed and how much cadmium they have in their body. The good news is, if it's only small amounts over long period of time, our bodies can work to remove the cadmium. If it's more cadmium than that, longer term effects can include learning disabilities, kidney problems, lung problems, and cancer.
The best way to limit your contact with cadmium is to quit smoking, and not allow smoking in your home. Additionally, be careful with reusable batteries, especially around kids, and watch out for costume jewelry. Other than that, the risks are relatively low unless your job exposes you to cadmium or you live near a factory that releases cadmium.
