Case Study: Strategic Dust Exposure Assessment and Mitigation in the Construction Industry

In our recent undertaking, we visited a major construction company to evaluate dust exposure levels. Our objective was to assess potential health risks posed by inhalable and respirable dust, particularly focusing on Respirable Crystalline Silica, to improve the company's health and safety practices.

The construction industry is well-known for its inherent hazards and risks, with dust exposure being one of the significant health concerns. The dust generated during various construction activities, including cutting and laying concrete, has potential health implications and can lead to chronic diseases if appropriate control measures are not in place.

A particular concern is the presence of Respirable Crystalline Silica (RCS) in construction dust, especially during tasks such as the cutting and laying of concrete. RCS is a naturally occurring substance found in materials commonly used in the construction industry, such as sand, concrete, rock, and mortar. Inhalation of RCS can lead to the development of silicosis, a debilitating lung disease. Chronic silicosis may occur after many years of exposure to lower levels of RCS, and accelerated silicosis can occur after exposure to high levels over a shorter period.

In this context, a construction site specializing in infrastructure, groundworks, and reinforced concrete frame services initiated an occupational exposure monitoring program to assess the risk and implement appropriate control measures. Regular exposure to inhalable and respirable dust, and more critically, RCS, was identified as potential risks for the workers, particularly those involved in the cutting and laying of concrete. The following sections will delve deeper into the problem, the assessment process and results, the conclusion drawn, and the subsequent recommendations provided for better workplace safety.

Observations

Construction workers in pairs perform tasks such as laying concrete blocks, cutting concrete, and paving, exposing them to dust and Respirable Crystalline Silica (RCS). Safety measures like open-air sites, water tanks for dust suppression, and the use of Moldex half face masks, gloves, long-sleeve garments, and other specific PPE are in place. Site signage reminds employees about PPE usage, which is adhered to. Regular health surveillance, good housekeeping practices, and training about potential hazardous substances are implemented. CoSHH assessments are carried out regularly and briefings regarding health and safety matters are conducted monthly.

Heavy plant operatives at the construction site operate vehicles like dumpers, potentially exposing them to inhalable dust and Respirable Crystalline Silica (RCS). The site is open-air with natural ventilation and on assessment day, had dry, low-wind conditions. These vehicles aren't enclosed and don't mandate Respiratory Protective Equipment (RPE). However, gloves, long-sleeve garments, work boots, hi-viz vests, and hard hats are part of the mandatory Personal Protective Equipment (PPE). For specific tasks like concrete cutting, additional PPE, including protective glasses, face shields, and hearing PPE are necessary. Adherence to PPE usage is prompted by site signage and is well followed. The operatives are subject to regular health surveillance including lung capacity, dermal, audiometry, eye function, and vibration damage checks. Additionally, cleanliness is maintained, and training provided on hazardous substances, along with regular CoSHH assessments. Monthly briefings on health and safety are also conducted.

Results

The evaluation of the obtained results showcased varied dust exposure levels across different roles and activities at the construction site. The exposure of construction operatives to both inhalable and respirable dust and Respirable Crystalline Silica (RCS) was particularly significant. Certain activities, such as the cutting of concrete blocks, showed exposure levels that were within permissible limits but still significant, necessitating attention. For heavy plant operatives, the exposure levels were under permissible limits and deemed not significant. Nonetheless, it's worth noting that even low-level exposure to RCS and other dust particles can present health risks over time. Therefore, while the site's operations mostly adhered to Occupational Exposure Limits (OELs), these findings underscored the need for continued monitoring, review, and enhancement of health and safety measures to ensure ongoing adherence and to further minimize exposure levels where possible.
 

Value Delivered

The air monitoring assessments proved to be a significant asset for the construction company by identifying areas of potential health risks due to dust exposure and providing actionable recommendations to enhance workplace safety. Despite most results falling within Workplace Exposure Limits (WELs), the assessments revealed higher levels of inhalable dust and RCS exposure during specific activities, like concrete cutting, warranting immediate attention.
The study underscored the importance of implementing the principle of As Low As Reasonably Practicable (ALARP) in these areas. Recommendations included specific actions to reduce inhalable dust and RCS exposure, such as improving control measures and carrying out periodic exposure monitoring to verify the effectiveness of these measures. The recommendations to provide suitable storage for respirators and regular review of working practices added value by enhancing worker safety. Furthermore, advice on continual COSHH compliance, maintenance of local exhaust ventilation systems, and respirator use education served as a valuable roadmap to help the company elevate their safety standards, thereby protecting employees and mitigating potential health-related liabilities.