Concrete, a mixture of cement, water, and aggregate, is generally inert once fully cured. Health risks stem from specific components and activities involved in working with it, not the finished product. The primary concerns are the inhalation of microscopic dust particles released when cured material is disturbed, and direct skin contact with chemicals in the uncured, wet state. Assessing the potential health hazards requires understanding these two distinct exposure pathways: airborne dust and chemical contact.
The Cancer Link: Respirable Crystalline Silica
The most significant cancer risk arises when cured concrete is mechanically broken down by cutting, grinding, or drilling. These actions release Respirable Crystalline Silica (RCS), a fine, invisible dust. Concrete contains silica, a common mineral in the aggregate, which, when fractured, creates particles small enough to bypass the body’s natural defenses.
RCS particles are less than four microns in diameter, allowing them to penetrate deep into the lower regions of the lung. Once lodged, these particles cause inflammation and scarring, leading to severe lung diseases. The International Agency for Research on Cancer (IARC) classifies crystalline silica dust as a Group 1 carcinogen, meaning it is definitively known to cause cancer in humans.
A debilitating non-cancerous condition caused by RCS exposure is silicosis, which is a permanent and irreversible scarring of the lungs. Silicosis is strongly associated with an increased risk of developing lung cancer, highlighting the long-term damage caused by RCS inhalation. Exposure to this dust has also been linked to other serious respiratory ailments, including Chronic Obstructive Pulmonary Disease (COPD) and kidney disease.
Because the dust is not visible under normal lighting, workers can unknowingly inhale dangerous quantities during common tasks like sawing and grinding. The primary hazard is the airborne dust created during the modification or demolition of existing, cured concrete structures.
Chemical Risks in Wet Cement
Chemical hazards occur when the concrete material is uncured or wet. Wet cement, the binding agent, is highly alkaline, typically possessing a pH around 12.5. This high alkalinity makes wet cement caustic and capable of causing severe chemical burns upon prolonged skin contact.
These injuries, known as “cement burns,” are insidious because the high pH can damage nerve endings, delaying the sensation of pain. A person may not realize they are burned until hours later, potentially requiring surgical treatment like skin grafts. The alkaline solution also facilitates the penetration of water-soluble substances, causing irritant contact dermatitis.
A separate concern involves trace amounts of hexavalent chromium (Cr(VI)) found in Portland cement. Hexavalent chromium is recognized as a carcinogen and can cause allergic contact dermatitis, an irreversible skin condition. This allergic reaction is a common reason why construction workers must leave the trade.
Manufacturers often treat cement with a reducing agent, such as iron sulfate, to convert Cr(VI) into the less toxic trivalent chromium (Cr(III)). However, this reduction effect can diminish if the cement is stored improperly or past its shelf life. Proper handling of wet cement is necessary for both immediate chemical burn prevention and long-term allergic sensitivity management.
Practical Steps for Reducing Exposure
Minimizing health risks involves controlling airborne dust and preventing chemical skin contact. For dust-generating tasks like cutting, drilling, or grinding cured concrete, engineering controls are the most effective method. Using “wet methods,” where a continuous stream of water is applied to the tool’s contact point, significantly suppresses dust generation by binding the particles.
Another effective engineering control is using on-tool extraction systems that integrate a specialized vacuum directly onto the power tool. These systems must be paired with a High-Efficiency Particulate Air (HEPA) filter vacuum, which captures microscopic RCS dust. Adequate ventilation should also be maintained, especially in enclosed spaces, to prevent dust concentration from building up.
Personal Protective Equipment (PPE) provides a secondary layer of protection. When working with dust, a respirator with a minimum N95 or higher-rated filter is necessary. For handling wet concrete, workers must wear waterproof, alkali-resistant gloves and long-sleeved clothing to prevent skin contact.
Good hygiene practices are also paramount. If clothing becomes saturated with wet concrete, it should be changed immediately, as the caustic material can seep through damp fabric. Exposed skin should be washed thoroughly with water and a mild soap after working with any form of concrete. Workers should avoid sweeping dry concrete dust, opting instead for wet sweeping or HEPA vacuums.