Lead Cables: A Past Threat or a Present Danger to the UK?

31-07-2023 | By Robin Mitchell

A recent report from the Wall Street Journal has highlighted that lead cables still in active use could be poisoning underground water sources, but while this may be the case in the US, the UK is hardly at risk. What challenges does lead infrastructure pose to modern life, why is lead not an issue in the UK, and how can engineers make design decisions today to make the future easier?

Wire isolation with heat shrink tubing in front of a blue fence against a background of green trees. Illustrating the process of wire protection using heat shrink tubing.

What challenges does lead infrastructure pose to modern life?

While it may seem stupid by modern standards, lead was highly popular in the past for making water pipes and electrical sheathing. To understand why lead was a popular material for thousands of years (even the Romans made their water pipes from lead), we have to first look back at history and understand what tools and materials were available.

Before the invention of modern manufacturing processes, everything had to be made by hand, and while some machines did exist to help with large-scale projects (such as blast furnaces), human strength was the dominant force in the engineering world. At the same time, materials such as steel and copper were both expensive, meaning that designers would try to avoid such materials wherever possible.

So, imagine being an engineer in the 19th century who has been tasked with laying down hundreds of miles of water pipes in a city or thousands of miles of telecommunication cables for telegrams. The system needs to resist corrosion, have a high degree of reliability, and be installed cheaply. In these applications, choosing lead as the base material makes perfect sense.

As highlighted in a Wall Street Journal investigation, telecom giants like AT&T and Verizon have left behind a vast network of cables covered in toxic lead across the U.S. As the lead degrades, it ends up in places where people live, work, and play, posing a significant health hazard.

In water pipes, lead resists corrosion and therefore is capable of carrying water for decades without degradation. The other major advantage of using lead in waterpipes is that it can be easily manipulated, thereby simplifying the installation of curved pipes. 

In telecommunication cables, a lead sheath not only allows for corrosion resistance but the ability to easily melt and seal lead means that such a cable can be made watertight. Furthermore, as lead is highly malleable, a lead-sheathed cable can be easily manipulated, going around bends with ease.

The advantages of lead in construction are so varied that it is still used today in roofs. Lead flashing is a thin strip of lead that is formed between brickwork and roof tiles to create a waterproof seal. Once installed, lead flashing can last for up to 500 years, demonstrating its ability to resist corrosion and withstand the test of time.

But of course, lead is a heavy metal that is highly poisonous to life forms and is especially dangerous to children where their bodies are more readily able to absorb lead. This is why lead has mostly been phased out of modern life, with some examples being the RoHS and REACH directives from the EU.

However, even with the increasingly restrictive legislation against such materials, the infrastructure laid down decades ago (in some cases, centuries) is yet to be replaced, meaning that there are still those exposed to lead products, especially in the form of lead pipes. Unfortunately, removing all of this infrastructure is not trivial, often requiring large digging equipment and hundreds of manhours to locate and replace pipes and cables. Even with government help, this ageing infrastructure will remain in place for some time, introducing a health risk to the public. 

Is lead a problem for the UK telecom industry? Not likely!

Recently, an article published by the Wall Street Journal outlined the dangers posed by the vast number of lead-sheathed cables buried in the US. In their article, they go on to describe how independent testing has shown elevated levels of lead in drinking water and soil surrounding older buried cables and that if infrastructure companies do not take action soon, it could start to have real-world impacts on health. Furthermore, the WSJ claims that in many of the samples taken, the levels of lead exceeded guidelines outlined by the EPA, especially in areas where children play. 

While the findings in the US are certainly concerning, as the UK has used the same materials, is the UK under threat from its older infrastructure? In a recent article published by ispreview, they approached Openreach (BT) to find out if this is indeed the case, and if so, what is being done about it. 

According to Openreach, the UK does indeed have miles of lead-sheathed cables still in use. These are far less of a danger to the public as such cables were rarely (if ever) buried directly into the ground. Instead, these cables have often been put into conduits which allow for ease of maintenance while simultaneously providing a layer of protection for cables.

As such, cables in the UK are not in direct contact with the soil, thereby reducing the chance of lead poisoning. Furthermore, it was also stated that of all the lead cables currently in use, less than 5% are connected directly to homes and businesses. This means that most of the cabling is being used along roads and underground infrastructure, significantly reducing the danger to the public.

It's important to note that the situation in the UK is different from that in the U.S. According to a report by ispreview, the UK's lead-sheathed cables are often placed into conduits, which provide a layer of protection and reduce the chance of lead poisoning.

However, Openreach also commented on the findings from the WJS article, backing up the statement from AT&T, saying that the methodology used by the WSJ was flawed. Furthermore, it was also highlighted that one of the companies performing the tests is already compromised by a conflict of interest. 

However, it's worth noting that the telecom industry is facing significant challenges. As reported by the Wall Street Journal, telecom giants like AT&T and Verizon have seen their shares decrease significantly in the first half of the year. This is due to a combination of factors, including rising interest rates, slowing real-estate and construction markets, and the fading 5G cycle.

How can engineers make better design decisions for the future?

When looking at the situation with lead-sheathed cables in the UK, it is clear that engineers of the past had the future in mind. As all the cables were placed into conduits, they can be easily removed and replaced without the need to dig up vast amounts of ground. This simple decision allows engineers far in the future to remove lead-containing products with ease.

Despite these challenges, the telecom industry is also grappling with a new environmental liability. The Wall Street Journal's investigation revealed the risk from copper cables sheathed in lead that are remnants of the old Ma Bell network. These cables, although no longer used for new installations since the 1960s, still exist under the water, in the soil, and on poles overhead. The investigation found elevated levels of lead in soil samples near known cable sites, posing a potential health hazard.

The USTelecom trade group has stated that they have not seen evidence that these legacy lead-sheathed telecom cables are a leading cause of lead exposure or a public health issue. However, the market's response has been significant, with shares of AT&T and Verizon sliding 13% and 12%, respectively, since the report was published. This issue is likely to remain an overhang for the stocks and valuation for at least a few months and potentially longer.

The full extent of the problem and the ultimate financial exposure for telecom carriers holding legacy networks is still unknown. It's unlikely that the matter will be resolved quickly or cheaply. Lawmakers in Washington are already pushing the carriers for answers and threatening legislation. Furthermore, environmental groups have asked the Environmental Protection Agency to ensure the immediate removal of such cables from poles and other areas. The potential for major lawsuits from workers and affected communities also looms large.

In conclusion

while the UK's situation is different from that in the U.S., it's crucial for telecom engineers and the industry as a whole to learn from these challenges and make informed decisions for the future. This includes considering the potential hazards of materials like lead and taking proactive steps to mitigate these risks.

Now, it is hard to look into the future and decide what materials will be banned or how devices should be designed, but that doesn’t mean engineers shouldn’t think about it today. For example, identifying potentially carcinogenic materials and eliminating their use in products is one way to achieve this. Even if the compounds are still available on the market, in ten years’ time, they may not be. 

By removing those compounds now, devices that show up in the future will present a lower risk to those who find them. Furthermore, the removal of potentially dangerous compounds also helps with the future recycling process, thereby reducing the harm done to those who have to deal with the resulting waste.

As we move forward, it's crucial to learn from the past and make informed decisions about the materials we use. As Public Health England's Compendium of Chemical Hazards points out, lead is a cumulative toxicant that affects multiple body systems, including the neurological, haematological, gastrointestinal, cardiovascular, and renal systems. By being mindful of the potential hazards of materials like lead, we can create a safer and healthier future.

Overall, making informed and well-thought-out decisions today can be massively beneficial for any engineering project, and it is always essential that engineers think of the future when designing for today.

Profile.jpg

By Robin Mitchell

Robin Mitchell is an electronic engineer who has been involved in electronics since the age of 13. After completing a BEng at the University of Warwick, Robin moved into the field of online content creation, developing articles, news pieces, and projects aimed at professionals and makers alike. Currently, Robin runs a small electronics business, MitchElectronics, which produces educational kits and resources.