By Nadeen Abbas

Picture taken from GLE

Lead was found many centuries ago. This element’s story is a good example of the dramatic failure after a great success. When people first discovered it, they did not hesitate to use it everywhere and in everything. Lead was used in production for its brightness and the easiness while using it. People then started using lead in painting due to its special properties.  After centuries, they discovered many serious and dangerous consequences for using it. Nowadays, it is banned almost everywhere in some industries. Unfortunately, lead is not that safe to use almost everywhere. What is lead? Why it was used to use lead in paint? Why it is not safe to use? 

What is lead?

Lead (Pb) is a transition metal. It has relatively a low melting point, around 327°C. It also boils at 1755 °C. It is a bright metal with a metallic gray color. It is very soft, highly malleable, and It tarnishes when exposures to air. In addition, it is relatively poor conductor of electricity.

What was lead used for?

The previous properties make lead (Pb) a good material to be used in production and daily life manners. Babylonians used it for making plates, and Romans used it to make coins, water pipes, and for even cooking utensils. In the time ofAugustus Caesar, they discovered that it is not safe to use it for cooking matters since it is poisoning, but they did not stop using it in manufacturing. Unfortunately, people kept using it for hundreds of years in industry thinking it is only dangerous and poisoning while cooking or eating with.

 Why lead in painting?

As mentioned before, the softness and the brightness of the lead make it a good substance to be used in painting. Compounds that contains lead are colourful and appealing.For example, Lead (II) chromate (PbCrO4) is yellow, lead (II, IV) oxide (Pb3O4) is red, and lead (II) carbonate (PbCO3) is white. 

Lead-paints’ are very pigmented, so a small amount of painting is enough to paint a large area. In addition, some lead-paints as the white lead are not soluble in water which works as water-resistant. Also, lead carbonate can also neutralize the acidic decomposition products of some oils, so the coating stays tough, flexible and crack-resistant for long time.Lead also helps to speed up the drying of the paint.

What is the risk of exposure to lead?

            Scientists could not realize the dangerous and toxic effects of lead early because the symptoms do not show immediately after the exposure. In the past, the cumulative exposure for a long period affected many people who worked or lived in places where lead was present, so scientists did many researches on lead. Many biological symptoms were noticed on people who had a long time exposure to lead such as abdominal pain and cramps, headache, high blood pressure, sleep problems , loss of appetite which cause anemia, constipation, memory loss, exhaustion, and  kidney dysfunction. In addition, it affects the psychology of humans which cause irritability and aggressive behaviour.  For children, they noticed the lack of devolvement and delay in growth. People who were affected for a very long time or with a high dose suffered from stumbling, comas, vomiting and muscles weakness. Those various and serious symptoms are due to the different parts that are affected by lead. Because of the many and irrelevant symptoms, it was hard, and it took time to link all symptoms to one disease and cause until they connected them to lead. To sum up, the risk of exposure to lead is that it does not show the toxic effects immediately after exposure, and it affects many different parts of the body.

How exposure to lead?

            As mentioned before, lead was used almost everywhere in the past. People used to make kitchen utensils and to serve food. They also used it in the pipes of drinking water and fishing sinkers, which means lead goes directly into the body. It was also used in jewellery and kohl- eye makeup – which means it touches the skin directly. After discovering the dangerous and toxic effects of lead when entering the body, people stopped using it in ways that make it enter or touch the body directly. Unfortunately, they did not know about lead paints and how dangerous it is. 

            In the 20^thcentury, people used lead’s painting a lot, and to paint everything.  People used those paintings in toys which children usually chaw, so it goes directly to the stomach. Moreover, most houses were painted with lead paintings, any damage in these painted houses would produce ashes and small lead particles that people breathe, so lead enter the body, specially lungs. The ashes may also reach water sources that people use to drink. Keep in mind that these paintings may affect humans nowadays since many of the painted houses and walls still in a good condition or damaged. If they are in a good condition with no damage, they would be affected in the future by any disaster or while doing renovations and affect humans. Also, having damaged houses means that we have ashes moving in the air we breathe and may reached the water we drink.

What other alternatives than using lead?

            Many decades ago, people started using other metals in preparing and serving food. Some used silver, but most of them started using Aluminum since it is not poising, safe2 ,and cheap. For the water pipes, people have started using plastic pipes to deliver water rather than lead ones.

In painting, there are many replacements of lead.Titanium dioxide is used as a replacement of the white-lead paint. Its pigmentation is better than lead and it has low toxicity. Also, companies are using strontium as a drying agent instead of lead, and it is non-toxic.

Is there any band on using lead ?

            Many companies and industries stopped using lead in manufacturing. In addition, many countries are controlling the use and the import of lead. In the US, there are bands on using lead in painting since 1978. In addition, the European Union is controlling the use and import of lead chromate pigments since 2015.  

How to remove old lead paintings?

It would be better to remove lead from buildings in good conditions. First, make sure that there are no children or pregnant women near or inside the building and they will not be affected by the dust. second, make sure to cover everything in the room and seal the area you will remove the painting from. Third, make sure to cover all your body and wash your clothes after leaving the site, or throw them. Also, make sure not to drink or eat while dealing with lead.

 What to do to protect yourself from lead?

            Few people are still using lead while cooking food or serving it and they should have more awareness about the toxic metal they are using. In addition, people should check the old buildings if they contain any lead. In case you needed to enter a damaged building that contained lead, you should wear a mask and gloves and wash your hands and face properly while being near or inside it.  

References:

– Alternatives to Lead in Paint. (n.d.). Retrieved November 19, 2020, from https://ipen.org/site/alternatives-lead-paint

– Anne Marie Helmenstine, P. (n.d.). Here’s Why Lead Is So Poisonous. Retrieved November 19, 2020, from https://www.thoughtco.com/what-makes-lead-poisonous-607898

– J, B., J, R., & T., D. (2019, November 06). How Has Lead-Based Paint Been Replaced in Recent Years. Retrieved November 19, 2020, from https://zotapro.com/blog/recent-years-lead-replaced/

– Lead poisoning. (2019, December 20). Retrieved November 19, 2020, from https://www.mayoclinic.org/diseases-conditions/lead-poisoning/symptoms-causes/syc-20354717

– Lead. (n.d.). Retrieved November 19, 2020, from https://www.britannica.com/science/lead-chemical-element

– Red Lead Oxide. (n.d.). Retrieved November 19, 2020, from https://www.indiamart.com/proddetail/red-lead-oxide-1274551733.html

– Vincent Iannelli, M. (2020, February 03). Are Kids at Risk From Lead Paint in Your Home? Retrieved November 19, 2020, from https://www.verywellfamily.com/lead-poisoning-and-lead-paint-2634713

– Water Treatment Solutions. (n.d.). Retrieved November 19, 2020, from https://www.lenntech.com/periodic/elements/pb.htm

– What Material Are Your Pipes Made Of? (2016, October 28). Retrieved November 19, 2020, from http://www.accurateplumbingfl.com/accurate-plumbing/what-material-are-your-pipes-made-of/

Secondary authors:

• Alaa Al Mikkawi
• Abdel Aziz Kordieh
• Amira Fawaz
• Abir Hajj Houssein
• Carl Zoghzoghi
• Christelle Rassi
• Jawad Hmayed
• Malak El Kassamani
• Marc Darazi
• Mohammad Asaad
• Mohammad Daoud