Metal's toxicity, its other sources, explained

Host Amber Smith: Upstate Medical University in Syracuse, New York invites you to be The Informed Patient, with the podcast that features experts from Central New York's only academic medical center. I'm your host, Amber Smith.

The Food and Drug Administration is seeking to set a maximum limit for the amount of lead allowed in some baby foods.

Here to help us understand why this matters is Dr. Travis Hobart. He's an assistant professor of pediatrics and of public health and preventive medicine at Upstate, and also serves as medical director of the Central/Eastern New York Lead Poisoning Resource Center.

Welcome back to "The Informed Patient," Dr. Hobart.

Travis Hobart, MD: Hi. Thank you for having me.

Host Amber Smith: Now, why is there any lead in baby foods?

Travis Hobart, MD: So, that's a great question, and I think it may come as a surprise to a lot of people when they hear that there's lead in their baby foods. The lead really comes from the environment in which the food was grown or the way that the food was processed to become baby food.

For instance, if the food is grown near a place where there used to be lead paint or lead gasoline that got into the soil, then sometimes the rain may wash some of that lead into the soil where the food is grown, and so you may see contamination that way.

Host Amber Smith: Is there any way to tell which foods contain the most lead? It sounds like, I mean, where ...

Travis Hobart, MD: Yeah.

Host Amber Smith: ... where they're grown would be, you'd need to know that first, I guess.

Travis Hobart, MD: I guess I would say there's no practical way, looking at a piece of food, to tell how much lead is in there, if there's lead in there, how much is in there, in the spur of the moment.

But in general, we know that certain foods are more likely to contain lead than others, so probably the things that contain the most lead are the root vegetables, and a lot of that is just because they are in the soil, right? And so, if there's lead in the soil, the carrot, for instance, or potato is touching that soil, and so you might have some lead on the surface of it.

And the good news about that kind of lead is you can wash it off, before you cook the vegetable, or if you peel the vegetable, that would peel that off.

Unfortunately, some of those vegetables do absorb a little bit of the lead, too, in the roots generally, but that's a pretty small amount, and, hopefully, that can be limited by good farming practices and obviously trying not to plant in soil that's heavily contaminated.

In general, the leaves and fruit of plants grown in lead are not as contaminated, so while it may be absorbed into the roots, usually that's where it stops, so the lettuce or the tomato don't have nearly as much lead, if any at all, really, and most of the lead in those situations might come from, again, contamination that they're dirty when they're processed -- the soil gets on them during processing.

Host Amber Smith: What about other metals that may be found in the soil: arsenic, cadmium, mercury? Is there equal concern about those turning up in baby food?

Travis Hobart, MD: There is also concern about those, and those have a different set of health risks and different levels that show up in the food.

Probably the thing that has received the most press and also is the highest contaminant, in baby foods anyway, would be arsenic. I know there's a lot of talk about that over the past few years, about arsenic and rice. Typically, arsenic is found in rice. When people test baby foods, that's the main source.

And again, the reason that arsenic is in the rice is often because of the area that the rice has grown. and because arsenic is commonly found in groundwater sources, and rice is flooded -- as you may know -- rice is flooded during the growth and harvesting process, so a lot of water gets on the rice, and if there's arsenic in that water, it can get it on the rice, and it also can be absorbed by the rice. So that's one of the major other sources of the major other heavy metals that we sometimes find in baby foods, is in those rice cereals.

We're talking about FDA regulation. In addition to lead, there's been regulation on arsenic and trying to reduce the arsenic in rice, and there has been some reduction over the past few years of that.

In terms of cadmium, again, that's often washed from industrial uses, washed and runoff and that kind of things, gets into the soil, where it can soak through the soil and be taken up by plants. It's a little bit less likely to be in plants than either lead or arsenic, so I'd say it's less of a concern. But the thing that might be more of concern is that it can actually be taken up by the plants more readily than some of the other things, so into the leaves of your lettuce or something like that.

And then finally, mercury. The primary concern for mercury that people may have heard about is in fish. And that mercury actually, believe it or not, comes from burning coal primarily, so those coal-fired power plants, in addition to producing greenhouse gases and warming the planet, are also putting mercury into the atmosphere that then settles on the surface and in the water and primarily gets taken up in fish. And so that's often where you get exposed to that.

So most baby foods, per se, wouldn't have as much mercury because most baby foods are not fish. But if you were feeding your baby fish, you'd want to just be a little bit careful about which kind of fish you used. And the ones with the highest contamination of mercury are the tuna fish and shark and swordfish. There are resources online that tell you which fish might have mercury.

One other thing to be aware of here in Syracuse is that there is some mercury in Onondaga Lake, so you probably should not be eating fish, and especially certain types of fish, caught in that lake. And certainly if you're a child or a pregnant woman, you should definitely not eat any of the fish from that lake.

Host Amber Smith: So if you are a consumer at a grocery store, though, looking in the baby food aisle, or, I guess, anywhere in the store, is there any way to tell whether that particular jar contains food that has lead or unsafe levels of lead in it?

Travis Hobart, MD: There's not a good way to tell when you're looking at the food in front of you, which is what I think is a frustration for many parents when they hear this kind of news, that there's lead in the baby food, and there's no way to know what's there in front of you.

Probably the best recommendation I can give is to give your baby a variety of foods. Because as I was saying, that a lot of the lead is found in certain foods, but not as much in other foods. So even if you're giving your baby carrots some of the time that may have lead in it, you're going to give them apples and pears and other foods, broccoli, et cetera, that wouldn't have lead in it or much less likely to have lead in it.

So I think just using a variety of foods is kind of the key to minimizing exposure.

Host Amber Smith: Does organic, does the label organic, mean anything with regard to lead contaminants?

Travis Hobart, MD: No, not really, and I don't want to discount the idea of an organic food. Organic food has a certain meaning, and it certainly may have benefits. I'd say primarily those benefits are environmental. There are maybe some health benefits. You certainly reduce your exposure to pesticides and herbicides. So I think there's the health benefit there, too, for organic food, but in terms of lead, the organic label doesn't really seem to make a difference because that contaminated soil can kind of be anywhere.

So whether it's an organic farm or a conventional farm, it's not going to necessarily change whether lead was nearby and then contaminated the food.

Host Amber Smith: This is Upstate's "HealthLink on Air," with your host, Amber Smith. I'm talking with pediatrician Travis Hobart about lead in baby food.

The Food and Drug administration was estimating that new guidelines could reduce a child's exposure to lead by 25%.

Would that be an appreciable difference?

Travis Hobart, MD: Yeah, I think so. Of course, a child's exposure when you're talking about percentage is going to depend on what other sources of exposure they might have as well, but certainly if you're reducing it by 25%, that's going to make an appreciable difference, I would think.

But it is, like I said, it's contingent on where else they might be being exposed. In particular, while I'm concerned about lead in baby food, and I want to reduce the amount of lead exposure to all children, I think the primary source of lead exposure in kids is from their homes, from the paint in their homes, and in older homes, the paint from before 1978.

So if you have a kid that's living in a heavily contaminated home, then the percentage of lead that they get from their baby food is going to be much smaller, probably, than the percent that they would get from exposure to that lead in their living environment.

So certainly, it's important to reduce that in the baby food, but I think on those sort of individual levels and as a society, we should be also focused on reducing the lead in indoor housing and paint.

Host Amber Smith: Well, let me ask you if we can talk a little bit about why lead is so dangerous for children in particular. Why is it a problem or a concern?

Travis Hobart, MD: Lead is a brain toxin, essentially, so it causes problems. When a child is exposed at a young age, and when an adult is exposed, too, it damages parts of the brain, and we're much more concerned about kids being exposed because their brain is rapidly developing.

So during that rapid development process, if a child is exposed to lead during that process of brain development, they may have long-lasting effects from that lead. Those effects typically are seen in later years, during school, for instance, when children may have trouble with attention or trouble with behavior. They may affect how they're able to learn and how they're able to succeed in school and in life.

One of the major effects that we see is sort of what we call "executive function," which is your ability to make decisions and decide what to do with your day or with your life, et cetera. And so we know that kids exposed to lead at a young age are more likely to commit crimes, for instance, as teenagers, and the young women are more likely to get pregnant as teenagers if they've been exposed to lead in childhood. And we think there's some connection there, that maybe decisions that they're making are less considered because of that lead exposure as a young child.

Host Amber Smith: So it sounds like some of these young children who are exposed to lead, you don't find out about that until they're older. Can you reverse the damage that's been done?

Travis Hobart, MD: The damage is actually very hard to reverse. Some of it may be reversed if we identify it early and take away the lead exposure, because the brain is going through that rapid development.

They may be able to reverse some of it, but much of it is permanent. And the data on reversing it is all very new and sort of not established, so generally we think of this as being a permanent problem. And it is true that we often don't know at the time when a child is exposed.

Now, fortunately, in New York state, the law is that all children at age 1 and 2 are supposed to be tested for lead poisoning, so they're supposed to get a blood test to make sure if they've been exposed, because usually there are no symptoms. You wouldn't look at your 1-year-old and say, oh, I think he's been exposed to lead because I can see whatever. There's not a symptom of lead exposure, which is why your doctor should be testing your child, at age 1 and again at age 2.

Host Amber Smith: So if a child does the blood test at age 1 or age 2, and if the results come back and show lead poisoning, what's the next step?

What does the pediatrician do with that information? Is it too late to help, or is that why you have the test at that age, so that you can intervene?

Travis Hobart, MD: I'd say the question of "Is it too late to help?" -- I think no, it's not too late. I think, unfortunately, some of the damage may be done and may be not able to be fixed, but we can prevent future damage.

And so, for instance, if you see a child at age 1 that has a level of 4 or 5 or 6, we often see that those kids, as they grow and develop and explore their world further as they go from being age 1 to age 2, we sometimes see the level go up, so it may be 6 at age 1, and then at age 2, it's 25 or much higher.

The important thing is, when we do see that high level, and that's why we're so on top of it and the Health Department is involved, that's when we try to make sure that the child is not exposed further. So we've got to remove any lead exposure from the environment as best we can or remove the child from the environment by helping the family move to a new environment, so that either the lead in the environment is fixed, or we're able to get the family to another living environment, where they can be safer.

And, like I said, any kid that has a level above 5, that's going to trigger the Health Department to come to the home and do an inspection and look for those sources of lead and help the family or the landlord know how to repair them or mitigate them.

Either replace them or paint over the areas that are a problem, to fix them so that the lead is contained or removed from the home, and the child is no longer exposed.

Host Amber Smith: In your role as medical director of the Central/Eastern New York Lead Poisoning Resource Center, what concerns you about Syracuse in particular with regard to lead exposure?

Travis Hobart, MD: The biggest concern I have in terms of Syracuse is that it's an old city, and a lot of the housing was built a long time ago. We know that if the housing was painted before 1978, which much of it was because much of it was built in the teens and '20s and '30s (of the 20th century), then those environments are much more likely to have lead at some level in the home.

And unfortunately, we see that there's a disparity here, as well. So, in a home that may be a rental home, maybe the landlord and/or the tenant don't have the money, the resources to fix the wall when the paint is breaking down and deteriorating, then that lead that's buried deep in the paint layers and the wall can come out and settle to the floor, as dust, usually, and children can be exposed in that way.

So, those older homes, and especially those homes that may be in disrepair because of poverty, those are homes that are much more concerning.

And the other thing that I would mention, too, is that, unfortunately, some of this is created by our systems that have oppressed certain populations over in the past. So some areas of town back in the '30s and '40s, the banks wouldn't let a black person get a loan to live in a nice part of town. They were only allowed to get a loan to live in certain parts of town, so there was really overt racism there that meant that certain types of people could only live in certain parts of town. And, unfortunately, that meant that those areas of town didn't get the money, didn't get the resources to improve the housing over time.

And we still see those disparities now. Those parts of town are more likely to have limited resources. Those houses are less likely to be maintained well, and the kids there are more likely to have lead poisoning. So we have this legacy of historical racism that has led to kids today being poisoned by lead.

Host Amber Smith: I saw recently data said that 12% of black children had high levels of lead, compared with just 6% of white children. Is that the disparity you're talking about?

Travis Hobart, MD: Yeah, that's exactly right. And because of that racism, the history of who was allowed to live in certain parts of town back in the '30s and '40s by the banks, the banks and the government sort of colluded to make sure that the city looked in a certain way.

And so black children are much more likely to live in those parts of town even today. And those parts of town have less resources to repair the homes and make sure that they're safer for children.

And we also see that there's a disparity. In terms of the racial disparity, black children are more likely to be exposed, as you mentioned. There's also a disparity the further you get from Syracuse; out in Onondaga County as a whole, the rates go down the further you get from the city, again, because of differences in resources available. Those homes tend to have been built later the further you get out of the city and also tend to be people that are more well off and more able to repair the home and put resources into the home.

Host Amber Smith: Do you know what percentage of kids have an unsafe level of lead in their blood in this area of Central New York, and then how that compares statewide?

Travis Hobart, MD: In the city of Syracuse, it is about 11% of children that have an elevated lead level. In the county as a whole, it's down to about 6%, and actually I'm blanking on the number for statewide right at the moment, but what we generally see is that it is a localized problem in that most of the kids that we see with lead poisoning are in the cities, where, again, the housing is older, there's less resources to repair the housing. They're more likely to be renters as well, because the landlord may not be as attuned to the repairs as a homeowner might be, or attuned to the needs of the tenant as a homeowner might be.

But we generally see that across the state. Syracuse is similar to the other major cities across the state: Buffalo, Rochester, Albany -- they all have this same problem. New York City certainly has this problem.

Some cities have made a little more progress in recent years, I think. Rochester's a good example, that changed the laws a number of years ago, to make landlords more responsive, to force landlords to be more responsive to lead issues.

Syracuse has been working the past couple years to really put laws into effect to do that, so we see when you look at Rochester compared to Syracuse, you see a little bit of a decrease in the number of kids with lead poisoning because of some of those laws. But Syracuse has actually been working, working very hard in the last few years, to really address this issue.

Host Amber Smith: This is Upstate's "The Informed Patient" podcast. I'm your host, Amber Smith, and I'm talking with pediatrician Travis Hobart about lead poisoning.

So if I understand correctly, the majority of kids with lead poisoning today come from living in houses with lead paint. Is that how most of them are being infected?

Travis Hobart, MD: Yeah, that is most of the kids that we see. When the Health Department finds the source of lead, it's due to paint in the home. The most dangerous parts of the home are, the Health Department would tell you, are windows, doors, porches and floors. Those are the places that, most often, the paint is broken down, the moving parts of windows and doors or people walking on a floor, a porch being outside in the elements. Those are places where the paint breaks down more quickly, and the lead paint is more likely to surface.

Host Amber Smith: So, can you safely cover old lead paint with new paint, and that takes care of the problem entirely?

Travis Hobart, MD: Yes.

I wouldn't say it takes care of it entirely, but it takes care of it for a time, anyway. And there are even products that are really made for that, paint that is meant to really block the lead and keep the lead inside the wall.

And the Health Department can help with identifying those products and even sometimes, depending on the situation, sometimes providing some of those products to families to help them fix it. but even regular latex paint will cover it up to some degree.

But that said, anytime we're covering it up, it is a good solution, and it's an affordable solution. So it's good. It's worth doing. But it is also a temporary solution. Three, five years down the line, especially if you have kids that may be doing what kids do and damaging paint or horseplay and that kind of stuff, the paint may break down again, and it may need to be redone down the line.

In an ideal world, when we have this situation, in an ideal world, we would want to remove the lead, but obviously that's much more expensive and much more time-consuming, so it often isn't a viable solution.

Host Amber Smith: We talked about some of the effects of lead poisoning later in life and the impact on executive functioning. Medically, does the fact that you were lead poisoned in childhood have an impact on your cardiac health or your cancer risk, later, as an adult?

Travis Hobart, MD: Yes. I mentioned the sort of neurologic effects, the developmental effects, of lead as the ones we're primarily concerned about, especially in childhood. But you're correct. There are other effects of lead. So it does seem to be associated with some cancers, particularly like the gastrointestinal tract or the urinary tract cancers.

It also seems to affect the kidneys, and that can lead to high blood pressure, so there's definitely an impact on high blood pressure that's been determined in more recent years. So that seems to be a concern for people that may have been exposed in childhood that are now adults, wanting to make sure their blood pressure's under control.

And then also, sort of more acutely in childhood, but it can cause anemia, which is a problem, and also affects the child's growth and development, as well.

It's definitely got other effects besides just the learning and developmental effects that we see.

Host Amber Smith: I know community leaders are aware of this and working on it, and the county Health Department is involved. Are there other things that need to be done to rectify this at this point?

Travis Hobart, MD: There are several groups, and I'm part of a coalition of many of these groups that are working together to address this issue.

A couple of the things that we're focusing on, and actually the county executive has recently set aside a lot of money to help do some of these initiatives.

So I would say there are a few steps in the process that we're working on, I guess the most important being the sort of primary prevention to prevent a kid from being exposed, ever. So the way that that's happening is, we're working to try to make sure that more people, more construction workers and contractors, are trained to identify lead in a home and fix it in a safe way. And hopefully, as more housing gets repaired and renovated and rebuilt, we'll see less lead in the environment. So that's one thing that we'd like to see.

Kind of tied to that is some of the laws I mentioned earlier about making sure landlords are more accountable when lead is found in the home, to making sure that the landlord has an incentive to fix it. And that there's some punishment associated with not fixing it and making sure that punishment is enforced.

And also making sure that we're testing the houses more frequently.

And then also there's a lot of loans and grants available to landlords and homeowners that helps them pay for those repairs. There's federal government money now and some more local money that's been put into this problem to be able to fix the problem.

The next step that we work on is, even though it's required to test all children, we see that not all children are getting tested, so trying to identify ways where we can make sure that:

A -- doctors know that they're supposed to do the testing,

B -- that patients are able to get tested when it's recommended by the doctor.

And so, sometimes that means making sure that the testing is easily and readily available at the doctor's office or near the doctor's office, so they don't have to go to yet another place when they have busy lives and other children to care for.

The Health Department is going to, sometime, probably this year, institute some kind of mobile testing unit. That was part of the money that the county executive put aside to help make that more feasible for people to have the Health Department do testing in the community or testing at other locations.

And then finally, the other piece that we need to do is make sure that these kids that are exposed get the resources they need to succeed in life, even if they've been exposed, because we don't want to leave those children and those families hanging by not providing the help that they need to succeed. Because again, there are effects of lead poisoning that are permanent, but it's not a death sentence. Those children are still able to succeed and still able to be functioning and happy members of society.

We don't want to just leave them hanging, so making sure that they get appropriate developmental assistance, preschool and school education, et cetera, is really important.

And one of the other things that the Health Department is going to institute, based on a program out of Buffalo called Lead It Go, is to try to get families who've been exposed those developmental resources immediately, before the child necessarily shows any signs of developmental delay, but to get the resources immediately so that those problems can be identified immediately.

Host Amber Smith: Well, Dr. Hobart, thank you so much for your time.

Travis Hobart, MD: You're welcome. It's been a pleasure.

Host Amber Smith: My guest has been Dr. Travis Hobart. He's an assistant professor of pediatrics and of public health and preventive medicine at Upstate, and he also serves as medical director of the Central/Eastern New York Lead Poisoning Resource Center.

"The Informed Patient" is a podcast covering health, science and medicine, brought to you by Upstate Medical University in Syracuse, New York, and produced by Jim Howe.

Find our archive of previous episodes at upstate.edu/informed.

This is your host, Amber Smith, thanking you for listening.