Checklist Model to Improve Work Practices in Small-Scale Demolition Operations with Silica Dust Exposures

Custodio Muianga,James Lockey,Carol Rice,Thomas Lentz,Richard Niemeier,Paul Succop

doi:10.3390/ijerph9020343

Abstract

A systematic approach was developed to review, revise and adapt existing exposure control guidance used in developed countries for use in developing countries. One-page employee and multiple-page supervisor guidance sheets were adapted from existing documents using a logic framework and workers were trained to use the information to improve work practices. Interactive, hands-on training was delivered to 26 workers at five small-scale demolition projects in Maputo City, Mozambique, and evaluated. A pre-and-post walkthrough survey used by trained observers documented work practice changes. Worker feedback indicated that the training was effective and useful. Workers acquired knowledge (84% increase, p < 0.01) and applied the work practice guidance. The difference of proportions between use of work practice components before and after the intervention was statistically significant (p < 0.05). Changes in work practices following training included preplanning, use of wet methods and natural ventilation and end-of-task review. Respirable dust measurements indicated a reduction in exposure following training. Consistency in observer ratings and observations support the reliability and validity of the instruments. This approach demonstrated the short-term benefit of training in changing work practices; follow-up is required to determine the long-term impact on changes in work practices, and to evaluate the need for refresher training.

Highlights

The construction industry represents 5 to 15% of the economy of most developing countries and is generally among the three industries with highest work-related injuries and diseases
Recommended exposure controls in the reviewed work practice guidance approaches included dust extraction with local exhaust, use of control cab equipped with a high efficiency particulate air (HEPA) filtration system, water dust suppression system, and personal protective equipment (PPE) including respiratory protection
The control guidance sheets were available through internet systems, but with limited accessibility in Mozambique

Summary

Introduction

The construction industry represents 5 to 15% of the economy of most developing countries and is generally among the three industries with highest work-related injuries and diseases. An important part of construction operations is demolition [1], where the workforce is often from the informal sector; small-scale, self-employed contractors, and trade-related unskilled workers (including children less than 15 years old) often work at these temporary worksites. These small-scale operations involve physically demanding work and represent potential for exposure to many kinds of dusts, including crystalline silica, stone and concrete-based building materials. These demolition tasks include breaking up, dismantling, chipping, cutting, hammering, crushing, loading, hauling, dumping, and dry sweeping [2]. By observation in Mozambique, the process of small-scale manual demolition was composed of the following steps: (i) marking a diagram of the area to be demolished; (ii) breaking-up concrete and masonry using nonpowered hand tools such as sledge hammers, hammers, chisels, scrapers;

Methods

Results

Discussion

Conclusion