From Ancient Egypt and the Roman Empire to Today – Lead Exposure Remains a Deadly Concern

Lead toxification is an unaddressed global public health crisis, persisting as a primary concern since ancient times. 

The ancient Egyptians were among the first to extract lead and use it to create small sculptures and incorporate it into pottery glazes. Meanwhile, the Chinese forged coins from the metal and the Greeks applied it as a protective covering on ship hulls. Lead”s versatility also extended to the roofing material and bullets (lead shot).

By the first century AD, the Romans were extracting up to 80,000 tonnes of lead annually for their expansive water systems. They used lead to line baths and pipes, valuing its anti-corrosion quality, which makes it durable over time. 

In the Roman Empire, winemakers were known to use lead pots or lead-lined copper kettles. Later, people put lead acetate into wine and other foods to make them sweeter. Soon, lead also found its way into paint and cosmetics, such as face powders and rouges, resulting in widespread lead poisoning.

The first epidemic related to lead intoxication was noted in the 7th century. In 14 B.C., the Roman architect Vitruvius noticed ailments in workers who used lead on the job. In the first century AD, the Greek physician Dioscorides noted lead exposure, causing paralysis, swelling, and delirium.

This led to a decrease in lead usage, and during the Renaissance period, lead poisoning primarily affected painters, metal smithers, and miners. 

Historians believe lead poisoning even affected the Roman nobility. It has been suggested that Julius Caesar, who fathered only one child, and his successor, Caesar Augustus, who was completely sterile, were affected by lead consumption. In fact, it is widely believed that lead played a contributing factor in the fall of the Roman Empire.

Chemical analyses also suggest that lead poisoning may have contributed to the death of German composer Ludwig van Beethoven at age 57, who suffered from digestive problems, depression, irritability, and abdominal pain.

Today, China, Australia, and the USA are the largest producers of mined lead. Lead’s primary application is in lead-acid batteries, which are ideal for all types of vehicles. However, over the past several decades, as awareness about the negative effects of lead has increased, many countries have banned numerous lead products, such as lead piping, fuel, paints with lead pigments, and fishing sinkers.

Despite efforts to reduce lead usage, it can still be found in food cans, makeup, hair dyes, ceramic dishes, and crayons. The major source of lead poisoning in American children, particularly, has been exposure to house paint or lead-contaminated soil or dust.

What is Lead, and How is it Negatively Impacting Our Brain?

Lead (Pb) is a metal that is soft at room temperature and gray in color. It has a low melting point and high density. Found in abundance in the Earth’s crust, this element is easy to work with and, hence, was used widely in ancient times. While the widespread use of lead has been discontinued in many countries worldwide, it is still used in many industries, such as battery manufacturing and recycling, car repair, refining, and smelting. 

Throughout human history, lead poisoning has been reported to have severe effects, and it continues to wreak havoc even today. Alarmingly, there is no known safe blood lead concentration, and levels as low as 3.5 µg/dL are associated with learning problems and decreased intelligence. 

Once it enters the body, this highly poisonous metal is distributed to other organs—the liver, kidney, and brain. Lead is also stored in bones and teeth, where it can accumulate over time, impacting biological functions. 

Lead poisoning affects the functioning of the heart, specifically a reduction in the speed at which it contracts and relaxes. Fetal exposure can result in a wide array of risks during pregnancy, such as premature birth, stillbirth, miscarriage, and low birth weight. In males, chronic lead exposure negatively affects fertility. 

Prolonged exposure to this toxic heavy element has also been found to be the cause of anemia, which is a blood disorder in which the blood’s ability to carry oxygen has fallen. Exposure to heavy lead levels has further been linked to hypertension, renal impairment, and even death. 

This naturally occurring metal can have really irreversible adverse effects on human health, particularly on the development of the nervous system and brain. 

Lead poisoning is known to affect the nervous system and can result in decreased cognitive performance that measures nervous system functions. Young children, however, are far more vulnerable to lead poisoning than adults due to absorbing 4-5x the amount of lead they ingest. Not to mention mouthing and swallowing lead-containing objects like soil or dust and flakes from paint. 

Among children, undernourished kids are even more susceptible to lead due to the lack of other nutrients such as calcium or iron. 

As early as 1943, scientists have been aware of lead’s adverse effects on neurological development in children, which leads to lowered intelligence as well as behavioral problems such as erratic mood swings and difficulty processing information.

This is because lead easily replaces calcium, which is how neurons in the brain communicate. Replacing Ca2+ ions to cross the blood-brain barrier results in neurological deficits, which are exacerbated in children due to the ongoing development of their neurological and nervous systems. Also, their internal and external tissues are softer than in adults.

Severe lead poisoning can severely damage the brain and central nervous system, causing coma, convulsions, and even death. Those who survive the high exposure may suffer from permanent behavioral disorders and intellectual disability. 

As we stated, lead toxicity is a disease that has devastating effects on the human body. It disrupts our digestive, nervous, respiratory, and reproductive systems. It can cause bone disability and prevent enzymes from doing their usual activities. Overall, almost every function of the human body is affected by lead toxicity. 

Late in 2023, WHO noted in its report on the public impact of chemicals that the cardiovascular effects of exposure to lead alone may be 6x higher than previously thought. Together with the impact on the intelligence quotient in young children, this results in a global cost of lead exposure of US$6 trillion (6.9% of the GDP).

Exposure to lead has significant societal and economic costs, specifically in developing countries. Given the risk, there is an increasing need for technology that guards against lead toxification.

Affordable Device to Detect Lead Contamination

New research has developed a chip-scale device that can provide sensitive detection of lead levels in drinking water. 

As MIT postdoc Jia Xu Brian Sia stated: 

“It’s an unaddressed public health crisis that leads to over 1 million deaths annually.” 

However, testing the water for lead is not a simple process; it requires expensive and complex equipment. Also, typically, it takes days to get results. A simple test strip can be used, but it only provides a yes or no answer about the lead’s presence and absolutely no information on the lead concentration.

According to the current regulations by the Environmental Protection Agency (EPA), drinking water must have less than 15 parts per billion of lead. This concentration is extremely low, so much so that it is difficult to detect.

So, engineers at MIT, the University of Southampton in the UK, Nanyang Technological University, and Temasek Laboratories in Singapore, along with researchers from various companies, came together to build an inexpensive and compact system for detecting and measuring lead concentrations in water.

The simple chip-based detector, inside a handheld device, provides almost instant measurement of the metal using only a drop of water. It can find lead concentrations of as few as 1 part per billion (1 ppb) with high precision. 

The new technology, which can be all set for mass usage in the next couple of years, potentially enables considerable progress in addressing a severe health issue that continues to persist globally.

Published in the journal Nature, the study aimed to find a simple detection method based on photonic chips, which measure using light. However, the challenge was finding a way to attach crown ethers to the surface of this photonic chip. Crown ethers are ring-shaped molecules that can carry specific ions like lead. 

After working on this for years, the researchers finally achieved this through a chemical process called Fischer esterification, which, according to senior author Sia, “is one of the essential breakthroughs we have made in this technology.”

When examining this new invention, researchers found that the tech can detect lead in water at concentrations as low as one part per billion. The accuracy is found to be within 4% for much higher concentrations, and as such, it may also find its application in testing environmental contamination.

Moreover, the chip-based detector works in water with different levels of acidity. With a range of pH values of 6 to 8, the device is able to cover “most environmental samples,” as per Sia. The device has been tested with both tap water and seawater, and the accuracy of the measurements has also been verified. 

While the new chip detector is a big innovation, much work remains to develop an actual product that can be widely used. This means a small laser joined with the photonic chip. According to MIT graduate student and lead author Luigi Ranno:

“It’s a matter of mechanical design, some optical design, some chemistry, and figuring out the supply chain.” 

That will take time, but the underlying concepts are straightforward. The device can also be adapted to detect other contaminants in water besides lead. These include radium, cesium, barium, lithium, copper, and cadmium. If this can be extended to radioactive elements, then the device’s potential can be tremendous. 

For this, Ranno noted that the system can be used with simple cartridges that can be swapped out to detect different elements. Each cartridge will use slightly different crown ethers to bind to a specific ion.

The device can particularly be used in developing countries where people don’t measure their water enough because the process involves collecting water, preparing the sample, and then bringing it to huge and extremely expensive instruments. 

To achieve high levels of accuracy, we currently need an inductively coupled plasma mass spectrometer (ICP-MS), which is “big and expensive,” requiring experienced technical personnel and days for sample processing.

But this can be completely changed with the new compact and portable device. Even those who aren’t trained can use it for on-site monitoring at low costs, making regular, widespread testing feasible.

The instantaneous detection of lead concentration, as well as other elements in the water, further holds the potential for allowing the real-time monitoring of the concentration of lead pollution in wastewater released from industries like lead smelting and battery manufacturing. This can facilitate the creation of monitoring systems for industrial wastewater. 

Cost has long been a challenge in lead detection, which this study also tackles. The work is compatible with large-scale, low-cost manufacturing.

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Who can Benefit from Solutions to Lead Exposure?

The chip-scale device can greatly benefit those involved in supplying water to people. American Water Works Company is one such firm.

American Water Works

This publicly traded water and wastewater utility company is planning to invest $28.3 million to build four new water storage tanks and rehabilitate ten of its tanks after spending $688 million last year on infrastructure upgrades.

This company has a market cap of $26bln, and its shares trade at $133.57, up 1.2% YTD. American Water Works has recorded revenue (TTM) of $4.3bln, with an EPS (TTM) of 4.91 and a P/E (TTM) of 27.18. The dividend yield, meanwhile, is 2.29%.

Besides water utility companies, the research can also be utilized by real estate firms to ensure that their properties are free from sources of lead contamination, while construction companies can incorporate these solutions into their product lines. 

Meanwhile, companies like EMSL Analytical are already offering lead testing services, firms like Brita produce water filtration products, and non-profit organizations like Lead Safe America Foundation provide resources for lead poisoning prevention.

Concluding Thoughts

Lead, a cheap metal that is highly malleable, corrosion resistant, widely available, and has a low melting point, has been severely affecting humans for a long time now. According to the WHO, an estimated 240 million people worldwide are exposed to drinking water that contains dangerous amounts of toxic lead. 

In the US alone, an estimated 10 million households are still having their drinking water delivered through lead pipes. This toxic lead can affect brain development in children and cause birth defects as well as produce many cardiac, neurological, and other damaging effects. 

Given the profound and chronic effects of lead exposure, the latest study holds immense potential. By allowing for pervasive and quantitative detection of lead as well as many other metal elements simultaneously, the portable device promises to be of huge use to humans and have a tangible impact on society.

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