DIP Episode 652 - OMBRS 1-The OSHA Lead Standard

All right welcome everyone my name is divine This is gonna be the occupational medicine board review a series This is gonna be series one and for me my goal with making this podcast is to really help people prepare for the Ahmed boards and You know from ABPM really help you understand the material Because I just feel like my experience with a lot of Ahmed material is memorization memorization memorization and I kind of want to clean that up a little bit Don't get me wrong. There's things you got to memorize. It's just the same with every exam But again, I'm really gonna try to help you understand some things and highlight the key points in a way that would really help you remember it for your test So if you don't know me my name is divine I've made a person that really loves medical education Have like more than 650 podcasts have made for the US Emily step one exams, right? You check divine intervention podcasts.com Made a ton of podcasts there, and I still keep making podcasts actually so But let's just you know settle on a series as well That will be helpful for people taking the Ahmed boards as many of you know, I'm an occupational medicine resident All right, so today we're gonna focus on the OSHA lead standard, okay?

The OSHA lead standard and The key thing to know is that this lead standard right to kind of start off there There's standards for general industry and the standards for construction right for general industries the code of federal relations You know 1910.10 25 for construction is 19 10 1926.62 if you take 26 flip the numbers you have 62 so Basically today You know that if you're taking the Ahmed boards you're probably gonna see a question on lead right they love to test lead They love love love to test lead right and I'm gonna try to hit things in kind of an organized fashion and try to make Integrations that the boards love to love to go after right so the first thing let's talk about the regulatory framework I think that's kind of like a big thing to know right so the thing is again General industry when you say oh divine is in general industry. What exactly do I mean by general industry? Well, I mean things like manufacturing battery plants Smelters radiator shops, right?

That's 1910.10 25 right but for construction think of renovating old buildings painting bridges demolishing old lead structures That's 1926.62 remember flip the 26 get a 62 right The construction standard was actually one that was added later the first one that was added was the general industry Standard right and the thing is in you know, you may wonder why did we worry so much about the construction standard We did because you know we realized that she there is a lot of lead painting a old in old buildings right and that was creating a pretty massive Occupational risks right so our own 1993 we added this a construction as standard right so for the boards Know that both of them exist. I need to know your thresholds code right so make sure you have these industries memorized Because they can write a question stem on your exams and they'll just give you some industrial pressing works in and then based on that You're supposed to deduce the exposure right so don't forget Let's melt in better manufacturing recycling right Manufacturing of lead pigment repairing reggaeders. That's a classic one working on firing firing ranges You know like gone firing ranges Bridges highway maintenance right construction especially construction With pre 1978 structures right that's something I want to keep in mind for your for your exams right so Let's talk about the exposure limits.

I think that's the next big thing I want to hit here exposure limits right your L and your PL Your action level and your permissible exposure limits right remember OSHA those P Ls NIOSH does are else they recommended exposure limits but the ones that are impossible at the Pels from OSHA right make sure you know your numbers. So let's run through the numbers right and I will encourage you write these down They will absolutely be on you exams right so what's the action level the action level for lead is 30 mic Micrograms per cubic centimeters of air 30 micrograms per cubic meters. Sorry cubic meters of air right as an eight hour time-witted average Right the PL is 50 micrograms per meter scooped right per cubic meters of of air right also as an eight hour ten time-witted average Right so what is the action level bio? What is the PL bio? Well the action level triggers monitoring and medical surveillance Right especially if you expose for like more than 30 days in a year right it triggers monitoring and medical surveillance But if you exceed the PL obviously right that's a higher number so you need to do more stringent things like What well you want to do more stringent things like engineering controls Personal protective equipment hygiene requirements biological monitoring and things like that Right so this is one workshop. I think I want to emphasize that people fall for right the action level and the permissible exposure limit They're airborne standards.

Those are things that are measured in the air not in the blood Measureting the air not in the blood right they apply to what workers breathe not to skin or in skin or ingestion exposure Okay, so don't forget you can get let poisoned from ingestion right You know like for example if you've worked with lead and then you're eating food and you've not washed your hands or whatever Right but the OSHA standard is written around air monitoring. That's very important Now let's talk about the air monitoring requirements, especially in terms of frequency right So the thing is there's this thing called initial monitoring when you do initial monitoring well If you expect you know before a worker starts working that hey this person could reasonably be at Or above the action level the employer has to do initial monitoring you have to do initial monitoring right now From that initial monitoring if the results come back below the action level you can stop monitoring But if the results are at or above the action level but below the PEL repeat every six months later to repeat every six months But if you're above the PEL then you need to repeat every three months.

Okay, that's a classic board question So you do your initial monitoring like oh gee the the Lead levels in the air between 30 and 50 Micrograms per meter cubed then you're gonna repeat it every six months if it's over 50 That's the PEL you're gonna repeat every three months every three months right every three months right Now let's talk about biological monitoring right let's talk about biological monitoring again. I've talked about the Airborne monitoring for the exposure limits. Let's talk about biological monitoring. Obviously you're gonna be measuring in blood Right, so let's get to the heart of it. Let's get to biological monitoring right again This is where the boards really love to test you right so how do you Check these out where you're gonna use the blood lead levels You're gonna use blood lead levels. That's the primary biomarker right it basically reflects Recent and ongoing exposure. That's why we like to use it right now What are the critical thresholds you need to know for you exams?

Well the first one is a blood lead level At or above 40 micrograms per desulator Blood lead levels at or above 40 micrograms per desulator If it's at or above that then that's gonna trigger Biological biological monitoring every two months literally every two months But if your blood lead level is at or above 50 micrograms per desulator That triggers mandatory medical removal medical removal protection I'm gonna talk about the fine details of that in a in a moment right and then if your blood lead levels are over 60 micrograms per desulator at any time that also triggers mandatory medical removal right So literally we'll remove you from that job where you're being exposed to lead It's like a hard threshold right 60s are hard threshold. So you're like define you just set 50 and now you're saying 60 Let me tell you something an easy way to remember this if your blood lead levels is 60 micrograms per desulator or higher You will always be removed medically medical removal protection for lead But If it's 50 or higher you're automatically removed as well if we're dealing with the construction standard If we're dealing with the construction standard for the general industry standard We take the average of your last three values right if the average of your last three values your three last measured Lead levels is 50 or higher then that also qualifies you for medical removal protection.

So let's clarify If your blood lead levels are 60 micrograms per desulator or higher at any time you're out If you're in construction and it's 50 micrograms per desulator or higher you're out If you're in general industry and be average of the last three is 50 or higher you're out as well Right another thing that also triggers medical removal protection is if the physician says you know what seems like Continued exposure to lead maybe a problem. Maybe you're getting pregnant or you already have like sequel I like is like you have restriple whatever and the physician is like Continued exposure to lead is not a good thing for you. That's another indication for medical removal protection Okay, so again remove or can be triggered one of two way one of three ways single blood level of blood lead level over 60 or Over 50 if you're working construction or the average of your last three of over 50 if you work in general industry or if the physician says You have something that makes continued lead exposure kind of worrisome right now What's gonna be the return to work criteria for these people right? Well, the thing is when you're removed when can you come back to work right because as an op-made physician You have to make these decisions Well, the thing is the person may return back to work when two consecutive BL Ls taking at least four weeks apart At below 40 micrograms per deciliter.

Okay, so below 40 micrograms per deciliter space at least four weeks apart Then you can return to work right now. Let's talk about this special thing called zpp You hear that we're thrown around zinc proto porphering right what's deal with zpp right the thing is it's like a Surgate for lead toxicity. It's a surrogate for lead toxicity Right, it's a surrogate for lead toxicity right because the thing is lead We know in the you know blocks the synthesis of him. This is part of how lead causes anemia right? So let inhibits an enzyme known as ferroquilates and what does ferroquilates do look at the name ferro Quilates it kill it's stuff to ferro ferro is iron right the Latin word for iron is ferro right ferroquilates Right, so basically it literally incorporates iron into proto porphering nine to make him right but if you shut down Ferroquilates then Ferroquilates cannot incorporate iron into proto porphering nine. So guess what is like okay? Who's available? Right zinc is like oh wow pro porphering nine is hanging around so zinc jumps on proto porphering nine right That's how you form literally zinc proto porphering because ferroquilates it's been inhibited It cannot put iron on proto porphering nine.

Okay, so the theory is if your zpp is elevated It tells us that man This presents lead has been affecting him synthesis It's a marker of like cumulative long-term effect not just recent exposure If you want to know more about recent exposure to lead the blood level is where it's at But if you're worried about like long-term cumulative exposure the zinc proto porphering levels are very very helpful Right, so again BLL reflects current and recent exposure zpp reflects a longer window right a longer window a longer window a longer window right a longer window Right, so if a if a worker kind of cleans up their lead exposure this can actually be a broad question What's gonna drop first the thing's gonna drop fastest is gonna be their blood level's their zpp is gonna take a while to drop Right, it's gonna take a while to drop. Okay, it's gonna take a while to drop Okay, so you can use the zpp to see like hey, what's your compliance look like over a long window over a long period of time Right, and then remember under the OSHA standard zpp is measured as part of the biological monitoring panel, right? A zpp that is above 30 micrograms per Desi leader a zpp above 30 my 35 sorry 35 micrograms per desi leader that's considered elevated that's considered elevated Right, so let's just again. Let's just do a quick Bort style question just to make sure that again these things I'm thick Teaching or kind of seep into your brain, right?

So what if they give you a question about like some 50 year old, you know battery recycling worker and you're told that you know Over the last six months. He's had his blood levels measured and one was 48 one was 52 one was 51 micrograms per desi leader Right, and then you know, it's be measured over the last six months and they are Axe who should this person be medically removed right Well first things first is this person construction a general industry Well, I'm gonna argue general industry right because the person works at a battery recycling plant Right, and then let's take it 48 plus 52 that's 100 plus 51 that's 151 151 divided by three is like 50.3 I believe right So the average average of the last three is over 50 right? So this person deserves medical removal protection So yes, this person should be removed This person should get medical removal protection right So again medical removal protection. I've talked about the criteria for it And one thing I just want to throw in as a tidbit is that medical removal protection is not just something we do with lead Another high-yield exposure you should know for you exams that medical removal protection applies to his cadmium Cadmium, that's another pretty high-yield one to know to know for you exams, right? So the thing is when you're removed from your job because you're exposed to lead because you meet the criteria for medical removal protection What exactly happens to you?

You know, I know you may be like oh divine some losing my job. I'm losing my livelihood No, you're not no, you're not actually according to OSHA lead standard the employer must maintain your earnings Your seniority your employment rights for how long for up to 18 months for up to 18 months So the employer cannot just send you home without pay now. You're gonna keep your job Right, you're gonna keep your pay rate. You're gonna keep your benefits. You're gonna keep your promotions Right, you're gonna keep your promotions, right? So the employer has a few options, right? If the employer can offer you a comparable job with lower-led exposure You can do that right But again, they cannot reduce your pay. You need to keep earning the same amount of money, right? Basically, this was put in place so that workers do not get economic retaliation, right? Because of a work related biological hazard like the employer has to do a better job of protecting the workers from from lead Right of protecting the workers from lead Okay, so please please please make sure make sure you know the criteria for the medical for medical removal protection Right, and then let's kind of talk about pregnancy and the let's stand that I think it's kind of helpful to to know Right, it's kind of helpful to know right? So pregnancy right it's a critical board perl Right, so the thing is the OSHA standard does not set a specific pregnancy blood-led level, right?

But the thing is myosh cdc they recommend that pregnant workers should avoid any Occupational lead exposure, right? And honestly the target blood-led level during pregnancy Is typically less than five micrograms per desliter Less than five micrograms per desliter Right, so because the thing is lead it's a reproductive toxin. It's a teradogen, right? So the thing is typically a pregnant woman may qualify for like MRP You know if the physician just says that hey, you're pregnant. I don't want your Your feeders to be exposed to lead, right? Because remember I said besides those hard numbers If a physician says that you seem to have a condition where Continued exposure to lead may present a problem for you. You're removed That also qualifies you for medical removal protection, right? So that's something I want to make sure that you know for your exams, right? And again, remember other things that can make a physician say I'm going to go ahead and remove you, right? Is if you have like renal disease or you have like high blood pressure or you have like neurological problems, right? These are all things that lead can trigger or exacerbate that can also qualify you for medical removal protection If a physician says so, all right, so now let's talk about the medical surveillance requirements, right?

Again, if you notice, I'm trying to interleave these concepts So you may be like well divine has said the same thing in a different context like three or four times I'm just doing this to help you remember this material better, right? So okay, okay, so let's talk about the ocean. Let's talk about from a medical surveillance and requirement a perspective, right? So again, remember Medical surveillance is mandated when you expose at or above the action level for more than 30 days per year for more than 30 days per year for more than 30 days per year, right? And when we're doing this medical surveillance, we typically start off with an initial medical exam, right? You know with an initial medical exam, right? So you know we take a detailed work history Take medical history, right? Hey, have you had prior late exposure? Do you have any symptoms of lead toxicity, right? We take your neurological history or productive history or renal history You can diversify history, right? And then we're going to do a physical exam that you know with emphasis on the neurological the renal the cardiovascular the hematologic systems, right? And we're going to check your blood led levels as I've talked about your ZPP, right? We'll check your CBC, we'll check your BUN and creatinine, right? We'll do a urinalysis, we'll check your hematocreat and hemoglobin, right? Because again, if we see that anemia, right? Especially a micrositic anemia, we're going to worry, right?

Because remember lead in hebits, he synthesis by shutting down ferocilities and another enzyme of discourse later known as early dehydrates, early dehydrates, right? So after this initial exam, right? What are the frequencies for periodic evaluation? Well, if we check your BLL at this initial medical exam and it's below 40, we're going to do a medical exam every two years at the minimum. You can do it more frequently, but that's the minimum. But if your BLL is 40 to 49, then we're going to examine you at least annually. We're going to examine you at least annually, right? If your BLL is 50 or above, that seems like medical removal protection to me, right? We're going to check you a little more frequently than that. We're going to check you a little more frequently than annually. We're going to check you very, very, very frequently, right? Very, very, very frequently. Now, one thing though is after you get this initial medical exam, what does the physician report to you and what does the physician report to the employer? You the worker and you the employer. This is a classic thing they love to test on the boards, right? So the thing is after every medical exam, what does the physician do? Well, the physician provides a routine opinion, a routine medical opinion to the employer. What does this opinion include? Well, number one, does the worker have any detected medical condition that places them at increased risk from lead exposure? You tell them that, right?

So you have any medical condition that, hey, that's going to push you at increased risk if you're exposed to lead. That's number one. Number two, any recommended limitations on the worker. Right? And then number three, you just put in a statement that, hey, you've been informed of the exam results, you, the worker, have been informed of the exam results and conditions of increased health risks. That's it. That's it. That's it. Right? So again, what are the three things that get reported? Number one, the worker, you tell the employer that, hey, you state if the worker has any detected medical condition that places them at increased risk from lead exposure. Any recommended limitations on the worker? Number three, a statement that the worker has been informed of exam results, right? And conditions of increased health risk. That's it. Right? But, you know, confidential medical information, specific diagnoses, no, the employer does not get that. Right? So the employer literally only gets the high points, conclusions and recommendations, not the full diagnosis. Not the full diagnosis. Right? Not the full diagnosis. Right? In fact, let's just do a question to kind of rehash this point. Right? So, you know, you have a question that they give you an exam about a physician that completes a, you know, periodic medical exam for a lead worker. Right? And this physician finds proteinuria and mild elevation in creatinine. Right? What should appear in the written opinion to the employer?

Well, the written opinion should basically state that, hey, that this worker has a detected medical condition because a medical condition was detected that places them at increased risk from lead exposure. Right? And then the physician should recommend limitations on lead exposure or removal. Right? But the specific diagnosis, oh, this worker has never happened to say, whoo, I saw protein in this worker's urine. No, no, right? And obviously, the worker is going to know the detailed findings, but no, the employer does not get specific diagnoses, please do not give specific diagnoses. Right? Now, let's talk about the engineering controls and hygiene. Right? This is something that quite a number of resources don't necessarily cover, but it's actually very high yield to know for the board exams. Right? So, the hierarchy of controls, they absolutely apply to the lead standard. Right? So, let's kind of run through, run through it. Right? So, obviously, right, like the best at the engineering controls, right? They have the primary method of reducing lead exposure. Right? Not respirators. Right? Respirators should be more of like a last resort. You should work more at the engineering level to reduce exposure. Right? So, the standard is explicit. Respirators are a last resort. They are not the first. Right? So, what are some of, so what are some examples of these engineering controls? Well, things like local exhaust ventilation, right? Processing closure, right?

Doing wet-dust suppression methods. Right? You know, and also substitution, if the person can work with things that are not, that, you know, accomplish the same task, but do not involve lead, then obviously that's a great thing. Right? So, if, for example, a task involves, you know, dry sweeping of lead dust, right? You know, you should do, you know, hepperva cumene, you know, wet-mopene, right? Wet-dust suppression methods, right? That's a key point you want to make sure you know for your exams, right? And then, one kind of strange thing that pops up on the board is, it's also important to know that a place that uses a lot of lead, right? The ocean standard actually mandates that, you know, they should be hygiene facilities and practices, right? That are very specific to prevent workers from ingesting lead, right? So, like, for example, an employer has to provide, like, you know, change rooms with separate storage for, like, workload for your workloads and your street clothes, right? They cannot be stored in the same place, right? They need to provide shower facilities. They need to provide hand washing facilities. They need to provide clean washrooms, like, you know, clean washrooms, clean lunchrooms, right? So, workers must not eat, drink, smoke, apply cosmetics in places where there is like exposure to lead, to lead, they cannot, so the employer must ensure that the workers, they wash their hands, they wash their faces before eating, drinking or smoking, right?

And you may wonder, like, what are these things targeting? Well, they're basically targeting the ingestion route of lead exposure, the ingestion route of lead exposure, right? And the thing is, the employer must also provide and pay for protective clothing, you know, coveralls, shoes, shoe covers, gloves, hats, face shields, right? And the employer has to be the one that lenders and disposes of these items, lenders and disposes of these items. It is very important to know you cannot take your lead clothes home, no, right? It's prohibited because you don't want to take it to your family members and then make them beneficiaries of your lead exposure. No, you certainly do not want that. All right. Now, let's talk about the respirator requirements. Let's talk about the respirator requirements, right? So, you know, we've talked about engineering controls. We've talked about administrative controls, right? When those controls cannot bring the lead levels in the atmosphere below the PL, then the employer must institute a respiratory protection program that is consistent with the respiratory protection standard, right? Like the 29 CFR, the Code of Federal Regulations 1910.134, right? So, if your and the respirator standard varies by exposure level, right? So, if the exposure level is at or above the PL, so 50 micrograms per meter cubed, but less than 500, then it is mandated that you get the half face, the half face, the half face air purifier respirator with a helper filter, right?

The half face air purifier respirator with the air filter. But what if the levels in the air between 500 and 2500 micrograms they need to do a full face air purifier respirator with helper filter, full face. So, if it's below 500, half face, if it's between 500 and 2500, full face, if it's from 2500 to 50,000, obviously it's higher, so you're going to need something a little more intense than that. You're going to need a proper, you're going to need a powered air purifier respirator with a helper filter or a supplied air respirator, right? And then if it's about 50,000 or the concentration is unknown, then you need to use an SCBA, you need to use a self-contin breathing apparatus, a self-contin breathing apparatus. Okay, so remember, again, about 50 less than 500 half face air purifier respirator, 500 to 2500, full face air purifier respirator, right? 2500 to 50,000, a helper with a helper filter or supplied air respirator is above 50,000, we don't know the concentrations, you're going to use an SCBA, an SCBA. All right, now, just to add in some pathophysiological flavor with this podcast, right? Like, you know, because again, sometimes the boards, they like to kind of throw in this pathophase, right? So, why is lead so problematic? Well, the thing is lead is a divergent cariah, it has a two plus charge, right? And the thing is lead is a zinc and calcium mimicker, lead is a zinc and calcium mimicker, right?

So, many of the things that calcium does in the body, lead does the exact same thing, right? So, if you can think of what calcium does, you can pretty much appropriate what lead does as well, right? And then I've also talked about how lead shuts down hym synthesis, that's how it causes anemia, right? What are the enzymes it inhibits in lead synthesis? It inhibits it, I mean, sorry, in hym synthesis, it inhibits early dehydrates and ferroquilities, right? And that's going to lead to accumulation of, you know, L.A. and protoprofering your in your erythrocytes, right? And then in your nervous system, lead is going to basically shut down like calcium mediate signal. Remember, to release neurotransmitters, to keep neurotransmitters moving, to keep your muscular transmission happening, neuronal transmission happening, you need calcium for that, right? Lead is going to disrupt that process, right? Lead can cause demilination, it can impair the release of neurotransmitter, because remember, calcium comes in into the neuron and then that's what causes neurotransmitters to be released, lead can impair that process, right? In the kidney, lead can mess up your proximal tubules. You can have a funkony-like syndrome, right? Whenever you have proximal tubules, this function, that causes like a funkony-like syndrome, right? It can cause interstitial nephritis, it can cause a bunch of problems, right?

So what are some of the classic clinical presentations you may see on your exam through lead toxicity? Well, from the neuro perspective, you can see Encephalopathy, right? You can see like a peripheral neuropathy that is typically moto, especially wrist drop, wrist drop is the classic one you see on exams, right? Sometimes you may have cognitive impairment, right? From the hematologist perspective, typically they're going to have anemia, microcytic anemia, microcytic anemia, right? Microcytic anemia, those sometimes it can be normal acidic, right? And typically if you do appear for all smear, you're going to see bisophilic stippling, right? Those bisophilic stipples are created by the buildup of ribosomal RNA that is not broken down. There is an enzyme known as pyrimidine, 5-prim nucleotides, pyrimidine, 5-prim nucleotides, that breaks down ribosomal RNA, that enzyme is inhibited by lead. So if that enzyme is not working, you won't break down ribosomal RNA, so it's going to build up. So you're going to have that lead, you're going to have those are bisophilic stipples, right? And then in the GI system, you know, you're going to have lead colic, you know, just this colic abdominal pain, constipation, anorexia, no one needs to eat. And then in the kidneys, right? Interestation of fritis, it can cause hyper-yorecemia, because the thing is when you have high levels of lead, it actually impairs, it actually impairs the ability of your kidneys to excrete your euric acid.

So you're going to have hyper-yorecemia, right? Sometimes they call this a subtle nine gout, right? And then in terms of the reproductive system, right? Let can cause reduced sperm motility in men, it can increase your risk of miscarriage, it can, you know, increase your risk of a preterm birth as a woman, right? And then remember, what are some things you may find radiographically with lead poisoning? Well, remember, in kids, right, don't forget your lead lines, your lead lines, your lead lines, your lead lines, your lead lines, your lead lines on the metaphysis, right? And then, you know, especially along your long bones, right? Those lead lines along your long bones, those are pretty classic, those are pretty classic. And then I don't want you to see a quarter of Burton's lines, B-U-R-T-U-N, Burton's lines, right? Those are like blue-grade lines along the gingiva, right? Along the gingiva, right? Along the gingiva, right? Although that's a lot of less common these days, right? Now, how do we treat lead toxicity? Well, chelation, chelation, chelation, right? Chelation, chelation, chelation, right? So, you know, people that are symptomatic or people that have very high BL Ls, right? We can use things like DMSA, right? So, dimer, capitol, succinic acid, sometimes it's called succimer, right? That's the oral agent of choice, that can be given oral. Right? What are some other options we have? Some other options we have are things like BL, right? British anti-luo site, right?

It's used when you have like very severe toxicity, what you have in cephalopathy. You can also use EDTA, right? EDTA, you know, calcium, dichotomym, edite, it's used as IV, right? But again, remember, remove your workers from exposure. That's what you should be doing. Save your workers, remove them from that exposure, remove them from that exposure, okay? Remove them from that exposure. All right, so let's just do some quick drills and then we're going to wrap up this podcast, we're going to wrap up this podcast, right? So, what's the action level for lead? 30 micrograms per meter cubed, right? 8 hour time weighted average. What's the PL? Remember again, that's 50 micrograms per meter cubed, right? Over an 8 hour time weighted average, right? Remember, those are measuring the air, the air and the PL measuring the air. Okay, now what's the air monitoring frequency if you're at or above the PL? It's every three months. What's the air monitoring frequency if you're between the action level and the PL? It's every six months. Okay, now what is the bloodlet level that is going to trigger, you know, bi-monthly biomonitry, right? If it's at or above 40 micrograms per deciliter, right? And then what is the single value that triggers medical removal protection? If it's 60 or greater, right? If it's 60 or greater, right?

At any time for anybody, general industry construction, or if it's 50 or greater for presiding construction, for general industries like the average of your last three, being over 50, being over 50, right? And then what's the bloodlet level for which we can say? Okay, you can come back to work after medical removal protection. Well, two consecutive samples, I've taken at least four weeks apart, that are below 40 micrograms per deciliter, right? And then what's that elevated ZPP threshold, right? It's a ZPP that is greater than 35 micrograms per deciliter in whole blood, right? In whole in whole blood, right? And again, remember for kids, you know, pregnancy, we want to really try to keep your lead below five micrograms per deciliter, below five micrograms per deciliter. Okay? And again, remember medical removal protection is you need to let and cut me, cut me, right? Again, we're going to keep 18 months of your earnings, your benefits, and things like that. They love to test that, right? So please, please, please, make sure you know these things, right? Make sure you know these things. I think I've kind of repeated these over and over again, so this should hopefully be locked in your mind. So thank you for listening to this podcast. Again, I really hope you find it to be helpful. Again, if you're interested in my other podcast, like my USMLA podcast and whatnot, I can check Divine Intervention Podcasts.com.

And then I'll start with another website called Divine Intervention Life Lessons.com, where I talk about life lessons. All right. So thank you for listening to me today. I will see you in my next episode. God bless you. Have a wonderful day. Bye for now. Thank you.

$30 \mu\text{g/m}^3$ as an 8-hour time-weighted average.

Every six months.

Blood Lead Levels (BL Ls).

Mandatory medical removal protection.

Two samples taken at least four weeks apart, both below $40 \mu\text{g/dL}$.

Ferrochelatase.

Cumulative, long-term exposure, rather than just recent exposure (which is reflected by BLL).

Ferrochelatase and ALA dehydratase (or ferroquilin).

1) Single BLL $\ge 60 \mu\text{g/dL}$; 2) Construction average last 3 $\ge 50 \mu\text{g/dL}$; 3) General Industry average last 3 $\ge 50 \mu\text{g/dL}$.

Less than $5 \mu\text{g/dL}$.

Only high-level conclusions and recommendations (e.g., "increased risk"), not the full diagnosis or confidential details.

Ingestion (via contaminated hands/surfaces).

Cumulative, long-term exposure, rather than just recent exposure (which is reflected by BLL).

Ferrochelatase and ALA dehydratase (or ferroquilin).

1) Single BLL $\ge 60 \mu\text{g/dL}$; 2) Construction average last 3 $\ge 50 \mu\text{g/dL}$; 3) General Industry average last 3 $\ge 50 \mu\text{g/dL}$.

Less than $5 \mu\text{g/dL}$.

Only high-level conclusions and recommendations (e.g., "increased risk"), not the full diagnosis or confidential details.

Ingestion (via contaminated hands/surfaces).