First ever meta-analysis on Indian lead exposure reveals link to devastating intellectual disability in children

October 12, 2018, Macquarie University
Credit: Alex Proimos/Flickr

New Macquarie University research has revealed the devastating disease burden associated with elevated blood lead levels in India. The results of the first ever meta-analysis of Indian blood lead levels found the burden of disease to be significantly larger than previously calculated, with negative outcomes on intellectual disability measures in children.

The research calculated the pooled mean lead level from data published between 2010 to 2018 to estimate the attributable disease burden in IQ decrement and Disability Adjusted Life Years (DALYs). The DALY is a measure of overall disease burden, expressed as the number of years lost due to ill health, disability, and early death.

Previous studies have estimated 4.6 million lead-attributed DALYs and nearly 165,000 deaths, far fewer than reported by the new Macquarie University study, which found that the total could be as high as 4.9 million DALYs, or, in other words, 4.9 million years lost due to ill-health, disability or early death as a result of the high .

At low levels, one µg/dL of lead contamination in the blood causes more than half a point of IQ decrement. For children living in India, whose blood lead level contamination is at almost 7 µg/dL, the impact on IQ is significant, explains lead author Mr Bret Ericson of Macquarie University and Pure Earth, New York.

"At a societal level, the bell curve of IQ shifts to the left, with more people falling into the intellectually disabled category, and far fewer in the gifted category. The potential impacts on a country's productivity and associated disease burden are, therefore, significant."

India's significantly elevated blood lead levels can in part, be attributed to battery smelting, which is poorly regulated in India.

"Given that a large number of people ride motorbikes or drive cars, and that the battery life is only two years, there are a significant number of used lead batteries recycled each year. These are often processed informally with little or no pollution controls, resulting in significant contamination across urban areas" says Mr Ericson.

However, there are also other known causes of exposure, including ayurvedic medicines, eyeliner, noodles and spices, which continue to cause the high levels of blood lead found in children.

Study co-author, Professor Mark Taylor, also of Macquarie University, notes that the implications of exposure are extremely detrimental, and with no evidence that the adverse outcomes remit with age, is calling for better regulation.

"We've identified a number of areas of exposure, but more work needs to be done to further determine the exact source, or sources, of the problem. There also needs to be better regulation and centralisation of battery smelting to combat preventable contamination."

Chronic low lead exposure has also been associated with , cardiovascular disease, anemia, and low birth weight, and premature mortality.

Explore further: Rate of elevated systolic blood pressure increases globally, along with associated deaths

More information: Bret Ericson et al. A meta-analysis of blood lead levels in India and the attributable burden of disease, Environment International (2018). DOI: 10.1016/j.envint.2018.08.047

Related Stories

Rate of elevated systolic blood pressure increases globally, along with associated deaths

January 10, 2017
An analysis that included 8.7 million participants finds that the rate of elevated systolic blood pressure (SBP) increased substantially globally between 1990 and 2015, and that in 2015 an estimated 3.5 billion adults had ...

Lack of fruits and vegetables increases global heart disease burden

March 7, 2017
Globally, increasing the consumption of fruits and vegetables could save millions of years lost to disability and premature death from heart disease, according to a study presented at the American Heart Association Epidemiology ...

Lead poisoning may hasten death for millions in US: study

March 12, 2018
Persistent, low-level exposure to lead over decades is statistically linked to some 400,000 premature deaths in the United States each year, far more than previously thought, researchers said Monday.

Air pollution causes millions of cases of kidney disease each year

November 5, 2017
The global toll of chronic kidney disease (CKD) attributable to air pollution is significant, according to an analysis that will be presented at ASN Kidney Week 2017 October 31-November 5 at the Ernest N. Morial Convention ...

Many cancers with largest impact on years of life lost linked to tobacco and alcohol

October 18, 2016
A new study finds eleven of the 15 cancers with the most impact on healthy years of life lost in the United States are closely-associated with two preventable risk factors: smoking and alcohol. The study, appearing early ...

Toxic waste sites cause healthy years of life lost

May 4, 2013
Toxic waste sites with elevated levels of lead and chromium cause a high number of "healthy years of life lost" in individuals living near 373 sites located in India, Philippines and Indonesia, according to a study by a Mount ...

Recommended for you

Self-lubricating latex could boost condom use: study

October 17, 2018
A perpetually unctuous, self-lubricating latex developed by a team of scientists in Boston could boost the use of condoms, they reported Wednesday in the journal Royal Society Open Science.

How healthy will we be in 2040?

October 17, 2018
A new scientific study of forecasts and alternative scenarios for life expectancy and major causes of death in 2040 shows all countries are likely to experience at least a slight increase in lifespans. In contrast, one scenario ...

Nutrition has a greater impact on bone strength than exercise

October 17, 2018
One question that scientists and fitness experts alike would love to answer is whether exercise or nutrition has a bigger positive impact on bone strength.

Father's nicotine use can cause cognitive problems in children and grandchildren

October 16, 2018
A father's exposure to nicotine may cause cognitive deficits in his children and even grandchildren, according to a study in mice publishing on October 16 in the open-access journal PLOS Biology by Pradeep Bhide of Florida ...

Study finds evidence of intergenerational transmission of trauma among ex-POWs from the Civil War

October 16, 2018
A trio of researchers affiliated with the National Bureau of Economic Research has found evidence that suggests men who were traumatized while POWs during the U.S. Civil War transmitted that trauma to their offspring—many ...

Many supplements contain unapproved, dangerous ingredients: study

October 13, 2018
(HealthDay)—U.S. health officials have issued more than 700 warnings during the last decade about the sale of dietary supplements that contain unapproved and potentially dangerous drug ingredients, new research reveals.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.