A new study has found that adult deaths from very low levels of lead exposure, is higher, perhaps ten times higher than previously expected! In line with some other recommendations from regulatory authorities, they concluded that there are no safe levels of lead exposure. Previously lead was primarily considered an issue in children and how it can affect their learning ability. We are now learning that it has much greater health effects than previously realised.
A study published March 12th in The Lancet Public Health estimates that lead exposure contributes to significantly more deaths from cardiovascular disease than was previously estimated. The study followed 14,289 adults for an average of 19.3 years and found that even low blood levels of lead (below 5 mcg/dL, which has previously been considered as safe) contributed to increased mortality, particularly from heart disease.
Lead in the blood is typically measured in µg/dL (micrograms per decilitre). Researchers used to think 5 µg/dL was a safe blood lead level. But agencies like the Centers for Disease Control and Prevention have recently determined there’s actually no known safe blood concentration for children.
Dr. Lanphear (the lead author of the study) and his colleagues believe the same may be true for adults. In the study, they found a strong correlation between lead in the blood and a higher risk of death from cardiovascular complications. Comparing the group with the lowest level of lead exposure (1 µg/dL or 10 parts per billion) to the group with the highest (6.7 µg/dL or 67 parts per billion), the researchers found a 70 percent increase in cardiovascular disease mortality risk and a doubling of mortality from coronary heart disease. This indicates that more lead exposure may lead to more heart trouble, and also that there is no safe threshold for lead exposure.
Lead exposure is linked to high blood pressure, hardening of the arteries and ischemic (coronary) heart disease.
Overall, people who had high lead levels (6.7 µg/dL) were at 37% greater risk of premature death from any cause, 70% times greater risk of cardiovascular death, and double the risk of death from ischemic heart disease, compared with people with lower levels (1 µg/dL).
“Our study calls into question the assumption that specific toxicants, like lead, have ‘safe levels’, and suggests that low-level environmental lead exposure is a leading risk factor for premature death in the USA, particularly from cardiovascular disease,” says Professor Lanphear. “Estimating the contribution of low-level lead exposure is essential to understanding trends in cardiovascular disease mortality and developing comprehensive strategies to prevent cardiovascular disease. Currently, low levels of lead exposure are an important, but largely ignored risk factor for deaths from cardiovascular disease.”
Children absorb up to five times as much lead as adults, and with their smaller bodies and developing nervous systems, it doesn’t take much to sicken them.
“That is why children who have been exposed to lead in early life have loss of IQ or shortening of attention span or other cognitive or mental health problems,” Landrigan explained.
Since the 1970s, lead exposure has been declining worldwide after the metal was eliminated from paint and petrol in the wake of research exposing its health effects.
Whereas increased awareness of the harms of lead exposure have resulted in substantial reductions in concentrations of lead in the blood over the past 50 years, the amounts currently found in adults are nevertheless 10 times, to as much as 100 times higher, than were observed in people living in the preindustrial era (700 to 1000 years ago), the authors note.
“What we are beginning to recognize — and we should have recognized it decades ago — is that metals like lead, arsenic, and cadmium are playing a much bigger role in the epidemic of cardiovascular disease than has been previously recognized.”
The findings have important implications for assessment of cardiovascular disease mortality.
Landrigan suggested that blood lead testing should become a recommended test in adult medicine, the way paediatricians now often screen children for lead exposure.
Other adverse health consequences of lead exposure include:
- Arthritis or muscular aches and pains
- Fatigue and irritability
- Fertility problems (both men and women)
- Gastrointestinal issues including nausea, heartburn, or constipation
- Gum disease
- Impaired concentration
- Muscle weakness or poor coordination
- Neurological challenges
- Numbness or tingling, especially in the hands and feet
- Poor circulatory health
- Thyroid dysfunction
Where may lead be coming from?
How do you know if you have lead in your body?
Symptoms of lead toxicity are not specific, they can mimic the symptoms of many other conditions. However, for peace of mind there are a number of options for checking your lead levels. The two simplest ways is to get your doctor to check your blood lead levels or do a hair test.
In Australia the recommended reference levels for blood lead are:
Blood lead – Adult female: <7mg/dL
Blood lead – Adult male: <10mg/dL
Blood lead – Children: <5mg/dL
Note that the Australian adult reference ranges are well above the levels in the study that are associated with higher mortality from cardiovascular disease.
A Hair Test is an easy non-invasive test that can indicate body burden of toxic metals from ongoing or previous exposure.