Health Effects of Lead
The health effects of lead have been recorded since ancient history, yet only in the past few decades have world governments chosen to take preventive and protective actions against exposure to the metal. Knowing the main health effects, primary routes of exposure, and how to safeguard one’s health can mitigate the dangerous short-term and long-term effects of lead poisoning.
Main health effects
While avenues of exposure will be explored later in this article, lead can enter the body in several ways including orally through ingestion, dermally through skin contact, or by breathing lead dust particles in the air. When we are continuously exposed to lead our bodies cannot naturally process enough of it out. It accumulates in our bodies and is primarily stored in human bone.
In the short-term, exposure to lead can cause headaches, nausea, abdominal pain, weakness, constipation, and fatigue. Part of the danger of lead poisoning is that these symptoms are attributed to a wide range of other ailments, causing some short-term lead poisoning cases to be overlooked.
Lead poisoning is most dangerous to young children but also can affect adults and newborns. Because lead can cross the placental barrier, pregnant women and fetuses are also vulnerable.
Main targets:
Nervous system
Lead is particularly damaging to the nervous system and is known to induce developmental neurotoxicity, harming mainly children. Developmental neurotoxicity refers to any negative effects that external substances cause to the developing nervous system. Effects include stunted growth, poor academic outcomes, and delayed development.
Lead is effective at causing damage to the nervous system because it can cross the blood-brain barrier by substituting itself for calcium ions, which readily pass through the barrier. The brain needs blood to function, and the blood-brain barrier serves as a filter that prevents harmful toxicants that are in our bloodstream from entering but lets the good things in (like oxygen molecules). Lead can imitate one of these good substances, allowing it to pass through the barrier and do damage directly to the brain.
Kidneys
Damage to the kidneys can occur even at low levels of lead exposure. The kidneys are responsible for vital functions like filtering blood, so this can lead to long-term chronic effects.
Reproductive system
In women, lead can reduce fertility, alter hormone production, impair menstruation, and cause a host of effects that can damage a developing fetus, including altering blood circulation and conception time.
In men, lead can reduce sperm counts and motility.
Cardiovascular system
Studies suggest that hypertension can stem from exposure to lead, which can subsequently result in outcomes like coronary heart disease and stroke.
Main Points of Lead Exposure
The primary source of lead exposure is contaminated drinking water in lead-laden pipes. Estimates indicate that up to 20% of lead exposure is caused by contaminated drinking water. Changes in water supply do not always alleviate these issues – in the example of Flint, Michigan, changing water sources caused more lead to leech into the drinking water supply due to the pH of the new water source.
Lead paint is also of particular concern for lead exposure. Before 1978, lead paint was commonly used to paint the interiors of houses. When the paint cracks, lead dust particles enter the air and are breathed in by the residents, putting lead into their systems.
Soil can also contain high concentrations of lead. While lead does occur naturally in the ground, the main cause of heavily leaded soil is emissions from industry and leaded gasoline. The EPA first began phasing out leaded gasoline in cars in 1973, which was not fully phased out until 1996. The emissions from these vehicles over the years have caused lead particulates to fall to the ground, contaminating the yards of homeowners. People gardening or children playing in their yards can bring these particles into the home on their shoes, clothing, and bodies, increasing the risk of exposure for those in the household.
Pb is the chemical symbol for lead.
Safeguarding health from lead exposure
There are several options to safeguard the health of residents from lead exposure. On an individual level, the Mayo Clinic recommends that people:
Wash hands, toys, and high traffic surfaces often
Test water and soil for lead
If living in a home built before 1978, test paint or take measures to mitigate lead paint
Test themselves and their children if they think they have been exposed to lead
Prevent children from playing in soil
Governments and regulatory bodies can make large-scale changes to safeguard human health. These actions include:
Providing free testing for high-risk areas
Subsidizing or fully covering the cost of lead service line replacement
Strengthen safety requirements for what constitutes safe drinking water
Provide community education and risk communication when lead is suspected
