Study: Lead Exposure Linked to Heart Disease

It's no secret that lead exposure is bad for your health. This naturally occurring metal is highly toxic to humans and animals alike. When lead enters the body -- either from eating food, drinking water or breathing air that contains lead --  it can lead to chronic toxicity or even death. And to make matters worse, there's new evidence suggesting that lead exposure causes more deaths than previously thought.

According to a new study published in the medical journal Lancet Public Health, lead exposure contributes to nearly a half-million deaths in the United States each year. For the study, researchers followed 14,000 participants over a 20-year period, paying close attention to lead levels in their blood and their rates of disease. At the end of the study, researchers found that participants with the highest levels of lead in their blood were 37% more likely to die from all causes and 70% more likely to die from heart disease than participants with the lowest levels of lead in their blood.

How exactly does lead exposure cause so many deaths, specially heart disease deaths? It's well known that lead exposure causes high blood pressure. People who are exposed to high concentrations of lead tend to have higher blood pressure readings than people with low or no lead exposure. High blood pressure, of course, is a major risk factor of heart disease. When someone suffers from high blood pressure, their heart and arteries become stressed, thereby increasing the risk of heart disease. Researchers say they were surprised, however, to discover that even low levels of lead exposure can increase a person's blood pressure.

As explained by the study's lead author, determining the exact number of deaths attributed to lead exposure has been nearly impossible. This new study, however, can help medical experts better understand the connection between lead exposure and heart disease.

"Nobody had even tried to estimate the number of deaths caused by lead exposure using a nationally representative sample of adults. But if we're underestimating the impact of lead exposure on cardiovascular disease mortality and other important outcomes beyond IQ, then it might have a big impact on the way we make investments in preventing lead poisoning exposure," said the study's lead author.

The bottom line is that no level of lead exposure is safe. Everyone should be conscious of lead and take the necessary steps to avoid exposure. If you believe your tap water has lead, for example, have it tested.