Does Socioeconomic Status Affect the Concentration of Lead in a Community’s Tap Water and What Can WE Do About It?



Does Socioeconomic Status Affect the Concentration of Lead in a Community’s Tap Water and What Can WE Do About It?


What is Lead? And What is it Doing in Our Tap Water?

Lead, a naturally occurring heavy metal, is found throughout the Earth’s Crust.  It has industrial uses and has been used in batteries, paint, and water pipes.  Because of its serious adverse health effects, in 1973, the federal government began phasing out lead in gasoline.  Its use was also banned in paints in faucets, solders, and pipes.

Why is Lead Toxicity Such a Big Deal?

Lead is a potent neurotoxin whose effect is particularly devastating to the developing brain of children. Studies have demonstrated that children can absorb 40% to 50% of an oral dose of water-soluble lead. Adults, in comparison, absorb only 3% to 10% of the dose. As such, lead poisoning has long been a major public health issue, particularly for developing children and pregnant women. This risk is especially high for infants drinking reconstituted formula. Since the effects of lead are irreversible, the only effective remedy is prevention. With federal regulation removing lead from gasoline and paint, the incidence of lead poisoning has decreased. However, drinking water remains a major source of lead intake, especially for those in the lower socioeconomic levels.

There is no blood lead level that is considered safe.

High lead levels can cause problems with learning and reading, irritability, hyperactivity, delayed growth, and hearing loss. At higher levels, lead can even cause permanent brain damage, convulsions, and even death.

Of particular concern are the effects of lead on children’s mental capacity. As demonstrated in this graph, there is a direct and steep relationship between blood lead levels and a decrease in IQ among children under the age of 6.

Other researchers have argued that elevated blood lead levels may lead to antisocial behavior.  Studies suggest that children with higher blood lead levels have increased rates of incarceration as adults for criminal behavior. 

As you can see from the graph below, the rise and fall in the blood lead level of preschool children closely resemble the rise and fall in violent crime rates some 20 years later.  This finding is somewhat controversial since there may be many other factors that can explain it, but it is an interesting theory to consider.

What is not controversial is the fact that many of the adverse health effects of lead are irreversible.  As such, the only effective remedy is prevention.  

How Does Lead Enter Our Diet?

Degrading, older pipes in the municipal system release lead in response to the municipal water source and the type of water treatment, such as disinfectants, used. A recent reminder of the importance of municipal water as a source of lead in the city of Flint, Michigan, which in 2014, in an attempt to save money, switched its water source from Lake Huron to the Flint River. This change leads to a significant increase in the lead content of the municipal drinking water resulting in a dramatic rise in the incidence of lead poisoning in the children of Flint. The long-term impact on the intellectual ability of the children will not be known for years. Since over 60% of the Flint residents are African American, and 40% have incomes below the poverty line, this incident renewed a national discussion about environmental justice.

Does the Tap Water of Poorer Communities Have Higher Lead Content?

For the state of Missouri, the short answer is YES.

To look at this question, I looked at the publicly available data on the Socioeconomic status of cities in Missouri and the lead concentration in tap water.   The Safe Drinking Water Act of 1974 established safety limits for 88 contaminants.  It also mandated public reporting of maximum contaminant levels (MCLs).  The socioeconomic indices of a community as measured by the Per Capita Income and Median Household Income are also available from the US Census Bureau.  The following 2 graphs summarize my findings.


Figure 1: 90th Percentile Lead levels vs. Per Capita Income.

The relationship between the tap water lead levels and per capita income quartiles is shown in Figure 1.  The difference in the lead level of the 1st Quartile (4.74±0.83 ppb) and  3rd Quartile (2.18±0.45 ppm) was statistically significant (p=0.02), as was the difference between the 1st Quartile and the 4th Quartile (2.62±0.28 ppb) (p=0.03).

Figure 2: 90th Percentile Lead levels vs. Median Household Income.

Figure 2 demonstrates Lead levels as a function of the Median Household Income Quartile. The 1st Quartile income group has significantly higher lead levels (4.62±0.88 ppb) compared to those in the 4th Quartile (2.44±.29 ppb). This difference was statistically significant (p=0.03).

In conclusion, this study demonstrates that at least in the state of Missouri, those communities at the lower socioeconomic scale have higher tap water lead levels than those at the higher end of the scale.

So, What Can WE Do About This Injustice?


The problem of lead in the water is not an issue that can be loved by one individual. It requires collective grassroots action by many. It can be spearheaded by a few who could educate and mobilize the others through education and advocacy. Our school’s Social Justice Club has come up with a practical and doable plan to deal with this issue in our local community. But our “call to action” goes to all of those who care about the health and environmental justice. You can follow our plan of action or modify it based on your local community’s reality. Please come back and share with us your experience.

1. Educate:  

      Before we can move our communities to deal with the issue of lead in tap water, we need to make sure people know that it is a problem.  We aim to do this by:

  • Having our Social Justice Club run an education campaign by putting it on our website (

  • Educating the parents of our classmates about the problem through our school newsletter.

  • Sending flyers to certain neighborhoods that are thought to have high lead levels in their tap water to make them aware of free water analysis, so they can find out the lead level in their drinking water.  This may motivate them to join together and pressure those in charge to do something to help.

2. Advocate:

     The main source of lead in drinking water is old and deteriorating pipes that leach out lead into the water.  The most effective solution replacement of these pipes.  It is estimated that replacing all of the lead-containing pipes in the US will cost approximately $30 billion.  That may seem like a lot, and it is, but let us put this number in perspective.  That is the cost of 3 aircraft carriers.  The cost of replacing all of the pipes in Flint would have been $55 million, less than one jet fighter.

     Only city, state, and federal governments are able to deal with the underlying cause.  But unless the people raise their voices, nothing will be done.  We need to:

  • Lobby our local, state, and federal representatives to dedicate resources to studying this problem and coming up with solutions, starting with those areas most affected.

  • We will be contacting our state representatives to set up a meeting to discuss this issue with them.

Works Cited

     Thank you very much for visiting my page.  I would love to hear your thoughts on the presentation and any constructive feedback you may have as to how I can improve it.  More importantly, please share any ideas you may have on how we can advance issues relating to environmental justice. 



  1. Adib,
    I really enjoyed looking at your presentation. It would be great if you could do a follow-up research project to see if there is a correlation between socioeconomic status and actual blood lead levels in children. Well done!

  2. Adib,

    Thank you so much for the presentation. This is a really important issue. Thank you for bringing it to our attention.

  3. Wow! The graph about the relationship between IQ and lead levels in childhood is scary!

  4. Adib,
    Great work! Your research and visual display created a powerful presentation that also displayed your passion and gave great insights to educate others. Thank you for bringing light to the inequities in our world.

  5. Hi Adib! I really enjoyed reading this research. It is very relevant to the ecocriticism unit my sophomore classes are working on right now and has some really helpful information I can share with them. Thank you!

  6. Hi Adib! I think this project was very well researched and you presented the information in a very compelling way. Specifically, your numbers about the price of replacing lead pipes vs. the cost of a fighter jet. I also appreciate your information about how we as citizens can impact communities by handing out flyers – in most cases, large problems like this often appear to have very difficult solutions, however there is a very clear way to help even if you are just one person. Great job!

  7. Hey Abih, I really enjoyed reading this project. This project is helpful for everyone so they can be educated. I like how you picked a topic that is meaningful to you and your community.

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