Historical Context of Lead and its Exposure in America
Lead exposure can occur through breathing in air with lead particles or swallowing particles of lead. This was a major issue in the mid-1900s as many types of consumer goods were manufactured with lead. Paint and gasoline were the two primary routes of lead exposure. Leaded gasoline is linked to both air and water pollution. Leaded paint was used on many household items, including on children’s toys and dishware. 30-40% of inhaled lead enters the bloodstream, 99% of that is retained in blood for 30-35 days. Over the next 4-6 weeks the lead is dispersed and accumulates in other tissues throughout the body.71 Long-term effects of lead exposure can range from subtle changes in neurocognitive function to a potentially fatal encephalopathy.
Since the 1970s, various forms of legislation have been passed to help reduce the blood lead levels in the US population. Prior to the 1970s legislation, 88% of children aged 1 to 5 years, had blood lead levels (BLL) of 10 μg/dL indicating a severe level of lead exposure.72Since the legislation, in 2018 this number has dropped 2.2% for children ages 1-5.73 Lead based gasoline phase out began in 1971 and was assisted by the invention of unleaded gasoline in 1975. The Lead-Based Paint Poisoning Prevention Act (1971) and the Federal Hazards and Substances Act (1973) helped to remove lead from consumer goods. Environmental acts passed by the EPA like the Safe Drinking Water Act (1974) and the Clean Air Act (1970) helped to remove environmental exposures to lead.73
While these legislative movements were effective at reducing lead exposure, case studies like the Flint Water Crisis inform that lead exposure is still a problem in America. In the next section we will be expanding on how some communities and cities are particularly susceptible to lead exposure and poisoning.
Lead in U.S. Water Systems & the Socioeconomic Implications of Lead Toxicity
Drinking water, as seen in the recent Flint Michigan crisis, is one of the main sources of lead toxicity because lead piping and lead-containing plumbing are still used in the United States.74 A study conducted in the USA between 2000 and 2003 found that roughly 3% of drinking water distribution systems, affecting a population of about 3300 people, had lead level levels exceed the 15 μg/L limit defined by the Lead and Copper Rule (LCR).74 Over time, water corrodes the inside of lead piping which increases water lead levels (WLLs) and when ingested increases blood lead levels (BLLs). The levels of lead toxicity in water are influenced by factors such as pH, alkalinity, temperature, and corrosion inhibitors. One of the major avenues and age demographic for lead toxicity is affected water fountains and tap water in schools, largely affecting the BLLs of school age children.75 These increase BLLs in school children has been linked to decreases in childhood intellectual developement.74
Lead toxicity, including but not limited to water systems, disproportionately affects marginalized populations and depreciated socio-economic communities. Older houses and low-income areas are more likely to contain lead containing paint, pipes, and plumbing.75 A study published in the Environmental Journal of Health, found that impoverished families were 11% more likely to have lead based paints in their homes than their affluent family counterparts, and Black households were 8% more likely to have houses with lead based paints than white households.76 Since people living below the poverty level and communities of color struggle to escape discrimination and find affordable housing, they gravitate toward areas in need of restoration and are therefore at a greater risk of lead exposure.75 Although costly, leaded plumbing should be replaced and water chemistry should be monitored for the effective correction of lead toxicity in US water systems.
Further Reading and Additional Resources
Linked below are resources that give current information on lead based policy and ways that organizations are working to reduce the blood lead levels of Americans.
This link will take you to the Environmental Protection Agency’s page on lead. Here you can learn about nation-wide policy on lead exposure and prevention.
https://www.edf.org/health/lead-toxic-legacy
This is a link to the Environmental Defense Fund’s page on lead, this organization is a nonprofit that focuses on environmental legislation and advocacy.
https://www.lslr-collaborative.org/
This link is to the webpage for the Lead Service Line Replacement Collaborative. This is a collaborative effort that is focused on accelerating the process of voluntarily removing lead pipes that lead to drinking water.
I thought this page was a really nice touch. I felt like this webpage was necessary because while this is a biochemistry class, the knowledge we learn only answers how lead poisoning works. It doesn’t answer why there is lead poisoning in our waters and pipes. An analysis of history and demographics is just as important to diagnose the problem of lead poisoning. My only comment for this section is that when you transition from talking about legislation to the Flint Michigan water crisis, you don’t have to explicitly explain in the next section what you’ll be writing about in the next section. I feel like the sentence before that one is already a very suitable transition sentence! This may just be my personal stylistic preference. Feel free to ignore this comment!
This page does a great job of placing the research in a real-world context. Just to make the page a bit more interesting, maybe add some images of corroded leaded pipes or the Flint drinking water!
Some sort of statistic of how much of the US population was affected by lead poisoning before the legislation that was passed in the 70s versus now or a statistic of how much of the US population currently still has lead in their system or is affected by long-term lead poisoning could be interesting if you could find it (nice job on the pun also; almost didn’t notice). Other than that, I agree with Bob that this more real-world and less biological/chemical context is very interesting and really enriches the whole project, and I agree with Henry that some images could spice this page up a bit. Overall, though, the information is conveyed well and the info itself is interesting.
ater pollution. Leaded paint was used on many household items, including on children’s toys and dishware. 30-40% of inhaled lead enters the bloodstream, 99% of that is retained in blood for 30-35 days. Over the next 4-6 weeks the lead is dispersed and accumulates in other tissues throughout the body.71 Long-term effects of lead exp
Lead exposure can occur through breathing in air with lead particles or swallowing particles of lead. This was a major issue in the mid-1900s as many types of consumer goods were manufactured with lead. Paint and gasoline were the two primary routes of lead exposure. Leaded gasoline is linked to both air and water pollution. Leaded paint was used on many household items, including on children’s toys and dishware.