The Heaviest Matter of the Universe

Flying whales, Gojira, primo music. This is how my mind works, and as such I bet you know where this is going? Today is about light chain amyloids. 

No not really, lead. Not the heaviest metal but it was used for sinkers for a while so it’s heavier than a fishing bobber. See? It all makes sense now. Heavy, lead, whales, Gojira. But let’s be serious now (yeah right….), and talk about lead. 

As I was recently looking for a new digs I saw quite a few homes. One of the topics always brought up, besides asbestos (which I will cover), is lead. Usually in the context of pain. The news of kids eating lead paint and the subsequent health issues stuck with me for some reason. Probably because of all the people who get sick, it’s especially “wrong” when kids get sick. Regardless, all ages have been affected by lead. 

Lead or Pb, yummm peanut butter……. Oh yeah, lead has been used throughout history as a (relatively) heavy metal that is soft, has a low melting point, and is easy to work with. The earliest evidence of its use dates back almost 10,000 years. It also is found with silver when mined so as silver became more desirable, the lead that was mined with it became more plentiful. It has been used in everything from makeup to wine, contraception to weaponry and more. 

It became apparent pretty early that lead led to some bad outcomes. A super cool hypothesis I read in the NIH article on lead poisoning: “some scholars have wondered whether the extensive use of sapa, a syrup of unfermented grape juice reduced in a leaded vessel and used as a preservative for wine, may have contributed to the downfall of the Roman Empire.” How cool. It also may have contributed to the prevalent idea that manual labor jobs were for “dumb” people, as they often worked with lead products for hours a day and we now understand better the effects on the human brain. 

So I already spilled the beans on lead leading to or have led to neurocognitive problems (I’m working on my lead puns). This can happen at very low levels in the blood, which is why even skin contact could lead to problems. The numbers vary but approximately 540,000 children between 1 and 5 years have elevated levels of lead in their blood, among adults it is about20.4 per 100,000 employee adults above 16 years of age. 

How is lead harmful once in the body? Glad you asked. Lead binds to a wide variety of proteins and is or acts as a cation causing it to bind to other molecules that need an electron. It is also very similar to zinc and calcium, which should not be substituted. Think back to my posts on anti-neoplastics, one of the mechanisms of action is to substitute DNA bases for others from the drug. It is a similar concept. Calcium is critical for the function of the heart, replace that with lead and that is bad news buddy. 

Calcium is also critical for your neurons through a variety of uses. This substitution leads to the most prominent picture of lead poisoning, neurocognitive decline. Long story short, lead does to the neuron what sticking a stick in the spokes of a bike does, causes a crash. In the end, the neurons die. Other effects that I don't quite understand are the disruption of neuron and glial migration, synapse formation, excitotoxicity, and others. Do you need more examples? Yes, you do. Lead also reduces the volume of certain areas of the brain leading to long term mental disabilities. In children, even small amounts can lead to learning issues, loss of memory, and can be correlated to ADHD and antisocial behavior. One author, economic consultant Rick Nevin, posited that lead exposure is directly related to crime rates. 

Anemia due to lead toxicity is caused by interference with enzymes that allow for the creation of heme and that support the cell integrity of erythrocytes. It is super, duper bad when your erythrocytes don't have integrity. Ever been lied to by an erythrocyte? Or had one steal the rims off your ride? You get the picture. 

Lead is taken up by bones and can be seen on x-ray of those with chronic exposure. GI symptoms are myriad with lead poisoning, from constipation to diarrhea. The endocrine system is thrown off, again where lead replaces needed enzymes and material for body processes. All this to say lead screws you up. There are many forms of exposure, but the common ones are from one's occupation, paint, urban soil, and water. Like many pollutants, lead can cycle from mining to paint or pipes, to soil or water then into we humans. Avoidance is the key when dealing with lead. Assuming you have the options. The EPA has good information on this and on the areas most at risk for lead in the environment. 

Treating lead toxicity, if severe, is usually done by chelation whereby a molecule binds to the lead and facilitates its removal from the body. Supportive care and treatment of the side effects from the lead are also called for. Nutritional support should be given to replace those which lead interferes with, such as calcium. But the best way, is to prevent the exposure, and if exposed, get the source away from the individual. 

Anyways, that is lead. That is all I have to say. Working a stretch of night shifts my brain melts during the day so the posts have been moving further apart. Cest la vie, I hope you survive. Actually, you might thrive with less of these going into the world. Love y'all, bye. 

References 

Image by Gojira

Lead from the NIH, EPA, WHO websites

Lead poisoning; a neglected potential diagnosis in abdominal pain by Shabani et al in BMC Gastroenterology 2020 

Lead toxicity from StatPearls at the NIH

How lead exposure relates to temporal changes in IQ, violent crime, and unwed pregnancy & Understanding international crime trends: The legacy of preschool lead exposures both by Rick Nevin in 2000 and 2007 respectively