Archives December 11, 2019

Editorial by Prakash Bhandari (073BCE104)

Cement is the most widely used construction material worldwide. Site civil engineers (who have the responsibility for quality control) and the workers (who work in concreting) are always exposed to cement. But how many of them are aware of the harmful effects of cement in their health? The answer is only a few or even negligible in a country like Nepal. At first we, engineers, must be aware of that and it’s our responsibility to deliver it to workers who work under our supervision. So let’s know about it. We all know that lime (CaO) (60-67%) and silica (SiO2) (17-25%) are the main constituents of cement. Besides these, there maybe traces of hexavalent chromium and some alkalis. All these compounds are poison for human health in different forms. A bag of cement contains particles of different sizes. It contains about 10% particles of size less than 2.5micron i.e. PM2.5 having the highest risk in air pollution. About 50% of particles are of size PM10 which can penetrate deep into the lung causing a number of pulmonary diseases like asthma, bronchitis, lung cancer, etc. Continuous exposure to cement dust may cause immediate or delayed irritation of the eyes. Depending on the level of exposure, effects may range from redness to chemical burns and blindness. Cement particle of any size if inhaled either by respiration or by oral tract, comes into contact with water in the upper gastrointestinal region and forms a hard mass like a cement block. Imagine the cement block in your intestine. Normal human skin has a pH values 5 to 6. But when cement comes into contact with water it forms calcium hydroxide which has a pH of range 12. This causes the caustic action of the human skin. The wet cement also has abrasive and drying properties. Continuous exposure of skin to wet cement allows caustic compounds to penetrate and burn the skin permanently. When wet concrete or mortar is trapped against the skin, for instance by falling inside a worker’s boots or globes or by soaking through protective clothing, the result may be first, second or third-degree burns or skin ulcers. Cement also results in some allergic reaction due to hexavalent chromium in cement. Almost all the engineers/ workers working in cement will develop an allergy to chromium, with symptoms ranging from a mild rash to severe skin ulcers. In addition to skin reaction, chromium can cause a respiratory allergy called occupational asthma. Symptoms include wheezing and difficulty in breathing. A person may suffer from both respiratory and skin allergies simultaneously. Cement poisoning can cause dermatitis, which is a skin irritation that is red and inflamed with small blister cement poisoning can also result in discoloration of your skin, which will progress to painful burns. The skin may become a dark blue color or maybe red and inflamed. This will be followed by fluid-filled blisters and can progress to open sores and even amputation. Silica found in cement is classified as a human lung carcinogen (the activator of the cancer-causing gene present in the lung). Additionally, breathing crystalline silica dust can cause silicosis, which in severe cases can be disabling, or even fatal. The respirable silica dust enters the lungs and causes the formation of scar tissue, thus reducing the lungs’ ability to take oxygen. There is no cure for silicosis and since silicosis affects the lung function, it makes one more susceptible to lung infections like tuberculosis. In addition to this if one has a smoking habit then he/she has to say goodbye to the world. Then how can we be safe from these hazards of cement?

Safety Precautions

• Never transfer cement products out of their manufacturer’s containers into unmarked containers,
• Read and follow the manufacturer’s instructions for use,
• Use alkali resistant gloves,
• Coveralls with long sleeves and full-length trousers,
• Waterproof boots high enough to prevent concrete from flowing in when we have to expose to concreting,
• Suitable respiratory protective equipment such as P, N or r95 respirator when cement dust can’t be avoided,
• Suitable eye protection where mixing pouring or other activities may endanger eyes (at least minimum safety glasses with side shields or goggles, under extremely dusty conditions.),
• Prefer ready mix concrete if possible,
• Always stay in the opposite of side of wind flow during concrete mixing,
• Don’t wash your hands with water from buckets used for cleaning tools.,
• Don’t prefer dry mixing,
• Provide adequate hygiene facilities on the site for workers to wash hands and face at the end of a job and before eating, drinking,
• Always wash your hand by cold running water after touching the concrete,
• Get medical support immediately if any risk is felt.
• You are a genius think more ideas to avoid cement’s disaster.

If you have any other idea to prevent/avoid cement’s hazards, please share by commenting below.

Editorial by
Prakash Bhandari
073BCE104
Pulchowk Campus