Blood lead levels

[joshuaray]

Does anyone know about blood lead levels? My baby just had his 12 mo checkup where they tested blood lead level. The reference range says:
“Birth - 6 years:

 

[wadebayo30]

@joshuaray What would you like to know?

I’m a child dev phd who had my infant test above threshold even though we had our victorian home tested and (we thought) remediated before he was born. Since that incident Ive started work on some big national lead projects, looking at cognitive outcomes in children who live in high lead homes. It’s not my main area of research, but Im pretty steeped in the literature right now, so AMA.

 

[asurfpro]

@wadebayo30 What have you done since your baby tested high to further remediate your home? And how do you suspect they were ingesting the lead?

 

[wadebayo30]

@asurfpro We had it retested by someone at the state level who didn’t just use dust samples, they used an XRF gun. Through some trial and error we realized the whole basement was completely coated and the cat was bringing it all over the house because her litter box was there. A real strange case according to the remediators. We paid a lot to have the basement fully remediated (sandblasted etc). BUT so many cities how have big grants set aside to help people assist in this type of remediation now - so don’t think remediation is out of reach financially.

My son was 9 mos when he tested high(ish). We were able to leave our house immediately and stay at a friends while remediation occurred so his levels dropped very fast. He’s almost 4 years now - has hit all milestones (benefit of me being in a developmentalist is I can track that easily). I sort of suspect he will have some mild ADHD, which is one of the most common effects of low level lead exposure, but he’s too young for any formal assessment yet. We have a lot of “protective factors” (parent education, diet, socioeconomic levels) so for now we do the best we can and support him with any bumps that come up along the way.

 

[justakitty]

@wadebayo30 I have five kids, the first four never had any levels above 3.5 when they were tested. The fifth tested in at 8.9 with a finger prick. I’ve been panicked since. I’ve tested (via swab tests) paint in our home and have found a few places where new paint chipped and lead paint was exposed. We’ve also had renovations work done (but while two others were babies and their lead levels were ok. We did have carpet pulled up and the original wood floors sanded while my fifth was an infant. His second test after 3 months (at his 15 month checkup) came back as 6. What should I expect as far as cognitive outcomes? I’m worried about delayed speech. What else should be on my radar with these lead levels. He is 1.5 years old and has really only said mama and dada and is just now trying some words like “up!” Any insight you can provide (even on this old thread) would be appreciated!

 

[wadebayo30]

@justakitty 3.5 is actually the current cutoff for flagging for “high” lead levels. It drops every few years because as they say “no amount of lead is good”. That being said, most research is correlational and nothing is determined for any given child, so even with the information provided don’t assume the worst.

First off - get your house lead tested. Really lead tested, by a professional. They have special reader “guns” that can test through 16 levels of paint and they will check every single nook and cranny. This will help you pinpoint exposure points. Ours was very unexpected.

Secondly, have you had a venous follow up check on this blood lead level? Finger pricks are notorious for having slightly higher readings because any lead on the child’s hand can influence them. You need a real blood draw to know what you’re working with.

In terms of outcomes - there are pretty strong correlations with BLL and IQ drops - somewhere around 1.5-5 IQ points per 5 µg/dL. Also strong correlations with BLL and ADHD, even at low levels. However, there is not much data on either age of exposure (at least below age 5) or length of exposure on outcomes. Also, things like parent education levels and socioeconomic status heavily influence outcomes. This is why none of this is deterministic - there are too many variables involved.

What I’m doing as both a parent of a high lead level child (7.5 µg/dL at 9 months) and scientist is - I’m just watching and looking for places to support when it’s necessary. If you’re worried about speech and have the means to do so - find a speech language pathologist. The “delay” may be nothing (18 mos is still pretty young) but a specialist will know even more than your pediatrician. What the BLL give us is a little extra info on places our kids might (or might not) struggle so we can just be a bit more aware.

 

[justakitty]

@wadebayo30 Thank you so much for your input! I value all this feedback and will look into all the great advice you’ve given. Thanks for taking the time to respond!

 

[thesavvy]

@wadebayo30 We live in a 100 year old home in the NE and just had inspectors at our house. We have some areas to work on in terms of remediation and hopefully our son's level goes down.

He tested at 5 mcg/dL at 22 months. What cognitive outcomes should be on our radar? If his level goes down significantly can I stop worrying or is this a forever worry now?

Sorry for jumping on your 15 day old comment but I'm in a reddit rabbit hole.

 

[wadebayo30]

@thesavvy Even a few years ago 5 mcg/dl was considered the threshold for flagging lead levels - so that’s still quite a low number in the scheme of things. With that level what is sometimes seen are mild attention deficits / adhd later in life, and maybe an IQ downtick of a point or two. But those are correlations and not some sort of predetermined destiny - each situation will be slightly different. In our situation, I’m just keeping this info in the back of my mind so that if my son ever needs a little extra support once he enters school, we can get it. At almost 4 years now, he’s not showing any issues and couldn’t be formally evaluated for things like adhd yet anyhow.

Unfortunately, this isn’t something that ever fully goes away - the lead stays in their bones and can leach out when they are sick or growing, temporarily increasing blood lead levels again. Extra unfortunately, there is not a lot of data looking at the influence of age of exposure and/or how quickly levels drop on later outcomes. A lot of research has been done on school-aged kids (those over 5 years) who have been exposed for years, many of whom continue to be exposed because their families can’t afford to move or remediate their homes. It’s safe to assume the quicker you can drop levels and remediate the situation, the better, but we can’t know for sure.

There are also lots of mitigating factors - for example, middle class and upper class kids show fewer effects from lead exposure than very low class (likely because of the other supports and enriching environments they have). So, again, nothing is deterministic here.

If I were you I’d take a deep breath, try to fix the situation as best you are able, and assume it’s going to be ok. His levels were low, you caught it early, and you care enough to look into ways to fix it - all of that will go a long way.

 

[kamga]

@joshuaray Everyone has some lead exposure because we live in a polluted world. Ideally we'd have none but it's not possible as long as you're breathing air, drinking water, and eating food.

 

[guevaraj]

@joshuaray You're right, there's no safe amount of lead and ideally you'd minimize any exposure kiddo has to inhalation or ingestion of lead. The blood level threshold is effectively the threshold that triggers further testing, pediatric conversations, or maybe health department visits to identify the source of lead, but that threshold has been continuously lowered as environmental lead levels have gone down.

It's generally standard of care to screen all at-risk kids (which includes kids living in 70s and older housing stock) with a finger prick or venous blood draw. If lead levels come back elevated, the doctor and family can then identify the source of the exposure and hopefully employ mitigation measures.

You can read the CDC guidelines here. In general, lead is not something you want to expose your children too, and it's also not something you need to tie yourself in knots in order to avoid (I say from my 1940s home) - employ common sense precautions (don't disturb lead paint, mop frequently, avoid older toys and play a bit away from buildings in case there's lead in the soil) and you'll probably be okay.

 

[oobobbi]

@joshuaray That number (3.5 mcg/dL) is the sensitivity of the blood test based on CDC recommendation (U.S.-based response, obviously). I definitely panicked about this after my son’s 12-month appt and didn’t understand how I should feel about the result (e.g., I would sure like to know if he has any amount of lead exposure, and why should I feel reassured about a

 

[zenom]

@joshuaray We are all exposed to lead so we will all have some levels of lead in our blood. Our ability to measure the concentration of lead in blood is limited by the technology used. Concentrations of 1-2 mcg/dL can typically be measured. The value of 3.5 was set based on a national (US) study of blood levels of children. 97.5% of children had measured concentrations below that value, so the test is a way to determine if your child is being exposed to higher lead levels that would suggest an intervention is warranted.

https://www.cdc.gov/nceh/lead/news/cdc-updates-blood-lead-reference-value.html