As the world has gained more insight into the disastrous effects lead can have on the human body, a large push has been made towards water quality testing. Perhaps most importantly, its links to neurological impairment have shed light on the importance of ensuring safe drinking water for all. Although it is well-known that lead is not good for the human body, its long-term health effects and the ways in which it is detected are not as well understood.
Lead is a naturally occurring metal found in the Earth’s crust, and has been a prominent part of human construction since the Romans used it in their aqueducts and water pipes (Morris, 2016). Unlike other metals, lead is easily malleable, explaining its constant use throughout human history (Morris, 2016). The negative effects of lead on human health began to gain more attention during the Industrial Revolution; however, lead pipes and paints within Canada were only officially banned in 1990 (Health Canada, 2021).
Lead is perhaps most dangerous due to its effects on the nervous system and brain development in children. Low levels of lead exposure may cause no observable symptoms; however, it can cause behavioural changes such as reduced attention span, intelligence quotient, and social behaviour in youth. Perhaps most distressingly, the neurological effects of lead currently have no treatment and cannot be reversed. Upon inhalation or ingestion, the chemical quickly travels through the bloodstream and is absorbed into many vital bodily tissues and organs, such as the brain, heart, kidneys, liver, and bones. Over time, most of the lead present will accumulate in the teeth and bones and is released back into the bloodstream during pregnancy, posing a large health risk to a developing fetus (World Health Organization, 2023).
Luckily, humans have recently been able to use many different methods to detect lead in drinking water, one of which is through the use of atomic absorption spectroscopy. Atomic absorption spectroscopy plays on the fact that every metal will absorb light at a certain wavelength due its unique electron configuration (Visser, 2021). For this reason, if a certain element is exposed to its specific wavelength spectra, it will enter an excited state and absorb photons corresponding to that energy level. This will cause a striped pattern to appear (Figure 1) as certain colours are absorbed by an element while others are reflected. A detector can then record this data and determine which metal elements are present within a given sample. Additionally, as the amount of light absorbed by a given element is directly proportional to its concentration, the amount of a metal present in a given sample can also be determined from absorption spectroscopy (Visser, 2021).
Sadly, the testing equipment required for the detection of lead through the use of atomic absorption spectroscopy is very expensive (Wu, et al., 2023). As a result, developing countries are often the most impacted by lead poisoning (Visser, 2021). However, as technology advances there is hope that innovation will allow for newer and cheaper methods of lead detection. When paired with international standards and funding, this may take the world one step closer to solving “the lead issue.”
Reference List
Health Canada, 2021. Lead Information Package – Some Commonly Asked Questions About Lead and Human Health. Government of Canada. Available at: <https://www.canada.ca/en/health-canada/services/environmental-workplace-health/environmental-contaminants/lead/lead-information-package-some-commonly-asked-questions-about-lead-human-health.html> [Accessed 18 February 2024].
Johnson, R., 2019. Ask Astro: How do scientists determine the chemical compositions of the planets and stars? | Astronomy.com. Astronomy Magazine. Available at: <https://www.astronomy.com/science/how-do-scientists-determine-the-chemical-compositions-of-the-planets-and-stars/> [Accessed 18 February 2024].
Morris, F., 2016. Before It Was Dangerous, Lead Was The Miracle Metal That We Loved. NPR. [online] 6 Apr. Available at: <https://www.npr.org/2016/04/06/473268312/before-it-was-dangerous-lead-was-the-miracle-metal-that-we-loved> [Accessed 18 February 2024].
Visser, D., 2021. Atomic Absorption Spectroscopy, Principles and Applications. [online] Analysis & Separations from Technology Networks. Available at: <http://www.technologynetworks.com/analysis/articles/atomic-absorption-spectroscopy-principles-and-applications-356829> [Accessed 18 February 2024].
World Health Organization, 2023. Lead poisoning. [online] World Health Organization. Available at: <https://www.who.int/news-room/fact-sheets/detail/lead-poisoning-and-health> [Accessed 18 February 2024].
Wu, D., Hu, Y., Cheng, H. and Ye, X., 2023. Detection techniques for lead ions in water: A review. Molecules, 28(8), p.3601. https://doi.org/10.3390/molecules28083601.