Thursday, July 28, 2016

Ask an Expert: Your Questions Answered by Curt DellaValle, Ph.D., Senior Scientist

EWG's community has lots of questions about chemicals in consumer products and food, and from time to time we do our best to provide answers. If you have a question for EWG's scientists, you can submit it here. Questions may be edited for clarity and brevity.

Please note: EWG can't provide medical advice. If you're worried that exposure to toxic chemicals in your household products is making you sick, consult your physician or another medical professional.

Is there a brand of furniture, including beds, that you can recommend to buy? We are planning on moving in the next 2 years and want to buy new furniture.

--Sandi S.

I'm getting ready to install new flooring in my home. Do you know of any brand of engineered wood that doesn't contain toxic chemicals? Same for carpet. 

--Kathy C.

In furniture, added flame retardants are the main concern. Flame retardant chemicals known as PBDEs, which can disrupt hormones, have for the most part been phased out in the U.S. But they've been replaced by a new generation of chemicals, such as Firemaster 550 and TDCPP, also known as Tris, which may be just as toxic.

A growing number of furniture manufacturers have completely or partially eliminated the use of chemical flame retardants. EWG has compiled a list of some of these companies and links to other resources that list such companies.

Any adult mattress sold today is unlikely to contain chemical flame retardants, relying instead on flame-resistant fibers and other barriers to the spread of fire. Children's mattresses are another story, and polyurethane foam is the greatest concern. Check the label and contact the manufacturer if you have questions.

With any manufactured wood product, there is potential off-gassing of chemical adhesives. Recently, Chinese-made laminate flooring sold at Lumber Liquidators was found to emit high levels of formaldehyde. To minimize exposure, look for flooring that is California Air Resources Board (CARB) compliant, or certified as ultra-low emission or no added formaldehyde. The EPA has further resources.

Like a lot of parents, I struggle with limiting screen time for my 8-year-old son. He uses an old iPhone for playing games. As I hear more about the dangers of cellphone radiation, I'm wondering if another gaming option would be safer. Do iPads emit radiation like cellphones do? Should we avoid all wireless devices?

--Kristen B.

Cellphones, tablets or any other devices that use cellular data emit radio-frequency radiation. The World Health Organization recently said this radiation possibly causes cancer. But if that's true, the risk is relatively small. And exposure to this radiation can easily be significantly reduced.

Turning on airplane mode will stop such a device from emitting radio-frequency signals. Wi-Fi radiation is less powerful than cellular radiation and there's no evidence to date that it poses any health concern. But Wi-Fi can also be turned off if you want to be especially precautious.

If cellular data or Wi-Fi are needed, then exposure levels can still be significantly reduced by simply keeping the device a short distance from the body. Rest the device on a pillow while gaming or watching shows, and use a hands-free device for calls.

Are CT scans as dangerous as researchers have suggested? I have had two pelvic CT scans and doctors have compared the exposure to the Hiroshima bomb.

--Michele S.

Unlike cellphones and Wi-Fi, CT scans and X-rays use a high-energy form of radiation known as ionizing radiation. It can damage DNA and cause mutations that can lead to cancer. There are clear benefits to CT scans and X-rays, but they should be used only when necessary.

To put the risk in perspective, the FDA estimates that at the high end of exposure, one CT scan increases your risk of dying from cancer by about five hundredths of 1 percent. Risk can add up over time, but a single scan is a minor concern.

The comparison to the Hiroshima bomb is true to a degree, but misleading. A CT scan is equivalent to the radiation energy some distance from the bomb's epicenter. And the distance from radiation matters: The sun emits radiation equal to billions of nuclear bombs every second, but we're far enough away to be safe from bomb-like effects.

For those who have a glass top or smooth top electric stove, what is the best nonstick cookware to use since we can't use cast iron?

--Stephanie F.

Don't give up on cast iron - you can bake with it in the oven. But to your point, I wouldn't recommend nonstick cookware at all.

Modern nonstick coatings are safer than those that have been phased out of Teflon ones, but they can still give off toxic fumes. Stainless steel, glass and even high-quality ceramic cookware are better options with fewer risks of leaching chemicals into food. If using pans properly, you shouldn't have a big problem with food sticking or with clean up. If you must use nonstick cookware, don't heat it to very high temperatures and don't use worn or scratched cookware.

Regarding pesticides on vegetables and fruits: If organic is not available does that mean we should not eat vegetables and fruits?

--Mark A.

Always eat your fruit and veggies. The benefits of a diet high in fruits and vegetables are too numerous to count. Diets that focus on whole, plant-based foods and limit red and processed meats, whether organic or conventionally grown, can reduce your risk of heart disease, diabetes, cancer and other diseases. Organic is an even better option because you can avoid some pesticide residues and other additives.

When organic is unavailable or cost prohibitive, you can seek produce with low amounts of pesticide residues from EWG's Clean Fifteen, while avoiding the Dirty Dozen. We also have tips for eating healthy on a budget.

Do the pesticides used on wine grapes become more concentrated in the wine- making process? Should we only be drinking organic wine?

--Joy E.

Pesticides have been detected in wine, but I'm not aware of them becoming concentrated. I would not be very concerned about pesticide residues in wine - the alcohol is of greater concern than a small amount of pesticides. But you may not want to add the potential risks from pesticide residue to the known risks of alcohol consumption. The best advice is to drink in moderation.

There seem to be differing opinions on nitrates and nitrites. I've read some articles that indicate there's no issue, but I'm not sure. I try to avoid these as much as possible, but can you cite evidence?

--Carol R.

I was wondering if you know of research on celery juice or powder in lunch meats, sausages and other food. It's a natural nitrate and is carcinogenic.

--Sveta G.

Nitrates and nitrites are complex. On one hand, nitrates can have cardiovascular benefits and can even be used as heart medication. But long-term intake of nitrates and nitrites have been associated with increased risks of cancer, especially of the stomach, under certain conditions.

Vegetables, particularly leafy, dark green and root vegetables such as spinach and broccoli, are a greater source of nitrates than meat. Yet red and processed meats are associated with increased risks of cancers, whereas consuming fruits and vegetables can lower cancer risks. Why is that?

It's not nitrates or nitrites themselves, but the substances they can help form in the body, that are bad for you. When we consume nitrates, bacteria in our digestive systems convert them to nitrites. The nitrites can then react with compounds known as amines and amides to form N-nitroso compounds. These compounds can increase the risk of some cancers. In our guts, the main source of amines and amides is protein.

Meats are a big source of protein. Processed meats preserved with nitrites can form these harmful compounds even before you eat them. Fruits and vegetables, on the other hand, contain compounds, including vitamin C, that can block the reaction that creates carcinogenic N-nitroso compounds.

As for celery juice or powder, your body makes no distinction between natural and synthetic nitrates or nitrites.

I work in a school. What can I do to reduce exposure to chemicals? We are having the school tested for mold, asbestos, and lead. What else should we test for?

--Natalie B.

Poor air quality in schools, municipal buildings, homes and offices can be a serious issue. In addition to the substances you mentioned, buildings may contain PCBs, or polychlorinated biphenyls. PCBs have been associated with risks of breast cancer as well as leukemia, lymphoma and skin cancer.

If a building was constructed before 1980, it almost certainly contains PCBs, which can be present in caulking and electrical equipment. When contained, they don't pose an exposure risk, but over time these substances can break down and create PCB-contaminated dust.

How do you know if you have lead in your water? Does lead cause cancer?

--Norma C.

Isn't there a danger in removing too many chemicals from drinking water? Fluorides are considered good for the health of one's teeth. Do you take this into consideration in your rating of filter systems?

--Walter M.

Several studies have linked lead exposure to an increased risk of stomach cancer. Data on other cancers has been largely inconclusive.

Lead in drinking water usually comes from pipes, which may be used by your local utility to deliver water, or in your home itself.

In Washington, D.C., where I live, the municipal water utility has an online map indicating where lead pipes exist. If your local utility doesn't have a map, contact the utility, check town records or ask your landlord to determine what type of pipes are in use. To see if the levels are of concern, you need to have the water professionally tested. In most circumstances, a water filter certified to remove lead is sufficient for maintaining safe levels.

There is no danger in removing "too many" chemicals from water. Pure water, essentially distilled water, is safe to drink. It may not be the best option, however, because small amounts of minerals, such as calcium and magnesium, have health benefits. Conversely, the benefits of fluoride to dental health are overrated, provided you practice good oral hygiene. Too much fluoride may even have harmful effects, especially for infants.