April 13, 2024: Lead
Good evening. Today we are going to talk about lead, that is, element 82 on the periodic table. Lead is the element with the highest atomic number with observationally stable isotopes, and consequently it is at the base of many radioactive decay chains.
Lead is also a severe environmental pollutant. The World Health Organization reports that almost one million people die every year worldwide from lead pollution, and 800 million children—one in three—have elevated lead levels of above 5 µg/dl. This is a level at which observable negative effects occur, of which there are many. A recent estimate is that lead is responsible for $906 billion per year of lost earnings due to neurological damage. This would place lead near the top tier of severe environmental problems. Several estimates have identified lead as much more damaging than most other environmental pollutants, such as asbestos, methylmercury, and ambient ozone, for instance.
Today I want to make a brief tour of where environmental lead pollution comes from and what can be done about it.
Once upon a time, leaded gasoline was responsible for at least 90% of human lead exposure. In 2011, it was estimated that the phaseout of leaded gasoline lead to $2.45 trillion of economic benefit and saved 1.2 million lives per year. I find it hard to believe that, in the not-so-distant past, people thought that putting lead into gasoline was a good idea.
The history of the phaseout was not exactly a straight line. There were short-lived bans as early as the 1920s, including a three year ban in New York City that started in 1923, in response to a horrid industrial accident. Following renewed awareness of the negative health effects in the 1970s, countries started adopting stricter lead content rules. Japan was the first country to ban leaded gasoline completely in 1986, and Algeria was the last in 2021. Incidentally, the phaseout in the United States was motivated at first by the introduction of catalytic converters, which were mandated to reduce air pollution; leaded gasoline damages catalytic converters.
We should step back and ask why leaded gasoline was ever used in the first place. Tetraethyl lead additives raise the octane number of regular gasoline and protects valve seats and high-compression engines. Leaded gasoline was invented by Thomas Midgley, Jr., who incidentally invented another product, Freon, which is now banned because of ozone depletion. When leaded gasoline was invented in 1922, Midgley knew full well of the damage to health, and Midgley missed the first sale of leaded gasoline in 1923 because he was laid up in bed with lead poisoning. The whole thing is one of the worst environmental scandals in history.
While leaded gasoline is banned for on-road vehicles, which was the vast majority of its use, it is still on the market today for, among other uses, aviation gasoline for piston aircraft. These are small aircraft that typically carry 2-10 passengers; kerosene jet fuel, which is used for commercial jets, does not contain lead. The EPA published an endangerment finding on aviation gasoline in 2023, which could pave the way for regulation under the Clean Air Act. Eliminate Aviation Gasoline Lead Emissions (EAGLE) is a consortium of the FAA and the aviation industry with the goal to develop unleaded aviation gasoline by the end of the decade.
At present, there are two main options for reducing lead in aviation gasoline. One of them is called 100VLL (very low lead), which is a suitable drop-in fuel for the 100LL (low lead) formula that is most commonly used today. But despite its name, 100VLL reduces lead content by only 20%. The other is UL94, which meets the ASTM standard for an unleaded fuel, but that isn’t a drop-in fuel and would require substantial engine modification for the fleet of piston aircraft. Work to develop an unleaded, drop-in fuel is ongoing.
Lead paint is possibly the most severe exposure today. Lead is added to paint to improve color vibrancy, drying time, and other properties, but the damage to health has lead many (but not all) countries to ban lead paint. In the United States, lead paint was banned in 1978, but many older houses still have lead paint, and this is a problem when old paint peels and cracks, especially when there are young children around who tend to put things in their mouths.
The Lead Exposure Elimination Project is a small but highly effective charity that advocates for lead paint bans in countries that have not already enacted them. Evidence is that their success in Malawi has yielded benefits far in excess of costs.
The recommended standard for “lead-free paint” is 90 parts per million. That is what we should expect if lead is not deliberately added. Truly lead-free paint is not feasible because other ingredients used in paint making still contain trace amounts of lead.
Even if lead paint is banned worldwide, there will remain large legacy amounts of paint. Studies of lead paint remediation have also found highly favorable cost-benefit ratios, and, while it is generally better to prevent rather than remediate pollution, remediation will certainly have a place for a long time.
The other possible most severe exposure for lead today is with recycling of lead-acid batteries. About 85% of world lead demand today is for this purpose. Especially hazardous is informal recycling of used lead acid batteries (ULAB). This is common in low-income countries where many people lack better options, but measures to protect workers from lead exposure are lacking.
Pure Earth is one of the major organizations working on clean-ups of informal ULAB recycling sites. Several studies, such as this one from the Dominican Republic, this one from Vietnam, and this one from Bangladesh show highly favorable cost-benefit ratios for ULAB site remediation.
I am not aware of good studies related to an informal ULAB recycling prevention cost-benefit analysis, but again it is generally the case that prevention of environmental problems is better that remediation. One especially interesting idea in this article is a deposit-refund system. A deposit would be assessed on lead-acid batteries when they are manufactured or imported, and then it would be refunded when a battery is recycled at a proper facility. This is done to some extent, and the theory behind the system makes sense.
Whenever we are talking about the harms of an informal industry, such as recycling, artisanal mining, or IUU fishing, we do have to keep in mind that we are talking about people’s livelihoods. People don’t engage in informal ULAB recycling because they like lead exposure; they do it because they are poor and have few other options.
The other question one might ask is, especially now with lithium-ion batteries becoming commonplace, is whether the economic case for lead acid batteries is all that great? The answer is, probably so for the foreseeable future, but for automotive applications, maybe lithium-ion will one day become the norm.
If you look at a periodic table, you’ll notice that the symbol for lead is Pb, which stands for “plumbum”, the latin word for lead. It is not a coincidence that plumbum has the same root as plumbing, as Rome’s advanced water system was notorious for the use of lead pipes. Since the mid-20th century, a popular theory is that lead poisoning, with the lead pipes being a chief cause, was a major contributor to the fall of the Western Roman Empire. This theory has since fallen out of favor, and Roman writers were evidently well aware of the existence of lead poisoning.
Congress banned lead pipes in 1986, but many such pipes remain in the ground. Old lead pipes leach lead into the water supply. There is an interesting idea to use electrolysis to remove lead that might leach. Last year, the EPA announced a plan to replace all lead pipes within 10 years, which would be funded through the Infrastructure Investment and Jobs Act, making the electrolysis solution moot.
The city of Flint, Michigan infamously experienced a crisis after a switch in the city’s water source lead to leaching from lead pipes. An estimated 6,000 to 12,000 children were exposed to high levels of lead during the crisis.
Lead adulteration in spices, particularly turmeric and paprika, is a more common problem than most people realize. This is done to enhance the taste and appearance of spices. This practice is especially common in South Asia—Bangladesh and India—and illnesses from contaminated, imported spices have been reported in the United States. There are calls for more stringent inspection of imported spices from the Food and Drug Administration as a result.
Since aluminum oxide from the Earth naturally contains trace amounts of lead, leaching from cookware, especially the cookware made from recycled scrap metal that is common in low-income countries, is a health hazard. Aside from lead, such cookware has been found to leach damaging levels of arsenic and cadmium. Use of a fluoropolymer finish greatly reduces leeching, but this adds to the cost of cookware—especially a problem in poor countries—can be difficult to mandate when there are many small-scale artisanal producers, and fluoropolymers pose health hazards of their own.
Lead ammunition for hunting and lead fishing sinkers are health hazards for people who consume game meat or fish and environmental hazards, especially for migratory birds. For this reason, it is recommended to use copper shot instead (if one is to go hunting at all). The Fish and Wildlife Service is considering a ban on lead ammunition on some public lands, and there have been other recent legislative actions. These measures are controversial; I won’t go further into it now.
The elimination of lead paint paint and leaded gasoline in the United States, as well as regulations from the newly created Occupational Safety and Health Administration (OSHA), led to a major decline in occupational lead poisoning, though there remain some problem areas, such as in some construction and manufacturing sectors, mining, e-waste recycling, and firing ranges. The danger is greater where illegal mining persists, as people engaged in illegal mining have little protection against lead exposure.
All right, I think that’s enough for now. Lead poisoning might look like a scary problem—and indeed it is—but for the most part it is a solvable problem. And many solutions have already been implemented, with the phaseout of leaded gasoline being the most important of them.
Quick Hits
Mackenzie Eaglen documents that the U.S. Navy has not been treated well in the latest budget proposal. The Navy is on track to lose ships. This comes alongside reports of serious delays and deployment problems at the Navy. Part of the problem, Eaglen argues, is that the Navy’s sporadic funding is causing supply chains to atrophy. I don’t think this point can be emphasized enough: having a robust defense industrial base is of existential importance to the United States and other free nations. The 2022 National Security Strategy described the 2020s as a “decisive decade” for American geopolitical needs, but I don’t see this urgency being reflected in actual decisions. Just today, American warships were deployed to protect Israel from Iranian attack, and American warplanes augmented Israel’s Iron Dome in intercepting drones. I hope this will be a useful reminder for Americans of why investment in national security is important.
Noah Smith wrote about the risk of a US-China war. There are also revelations that Chinese technical and logistical support for Russia’s war in Ukraine is much greater than was previously believed.
Cathy Young looks at the “intellectual dark web” and what went wrong with that movement. One especially salient point is on audience capture: when a person attracts a certain readership base, the author may feel compelled to produce content that satisfies that base, which can be a radicalizing force for authors.
The future of the child tax credit is looking very shaky right now, with several Senate Republicans expressing opposition. In the past I’ve written extensively about the issue of declining birth rates and that this is a serious problem. As far as I can tell, public investments such as the child tax credit are among the few credible policy tools for raising birth rates, and the lack of interest in this issue tells us how pathetic the pro-natalist movement is.
There has been much angst about layoffs in the video game industry last year and this year. Comparisons to the 1983 video game crash are overwrought, but it does look like an especially difficult time to be a video game developer, and it has been always been difficult. TechCrunch has some stats about layoffs in the tech industry more broadly. There were heavy layoffs early in 2023, and another, not quite as severe, round of layoffs this year. I would be very surprised if this is over.
And finally, although this is old news, I learned recently of a theory that name of Al Qaeda, which best translates into English as “the base” or “the foundation”, may have been inspired by Isaac Asimov’s Foundation series. Evidently Osama bin Laden was a fan. This is one of those things that sounds like it probably isn’t true. The name could just as well have been inspired by Zero Wing’s “All your base are belong to us”. Based.