Overview of the Industry
There were 9.9 million workers employed in construction in 2015.[1] Construction workers come from a number of trades and work in one of the most dangerous industries in the U.S. Over 1000 construction workers die on the job each year which accounts for about 20% of all occupational fatalities in the U.S.[2] Thousands more are likely to become ill and lose years of life or suffer reduced quality of life from occupational illnesses.
Because much of construction involves rehabilitation, maintenance, and demolition of existing structures, it is not uncommon for workers to encounter asbestos in older buildings or for painters, ironworkers or laborers to be exposed to high levels of lead when working on steel structures where lead still coats much of the nation’s inventory of bridges and other steel structures. Noise, isocyanates, asphalt fumes, solvents, man-made mineral fibers, welding fumes - which may generate elevated levels of hexavalent chromium and/or manganese and silica are just some of the more common health hazards encountered in all types of construction.
This section includes establishments primarily engaged in construction. The Construction sector comprises establishments primarily involved in the construction of buildings or engineering projects (e.g., highways and utility systems). But the term construction includes new work, additions, alterations, reconstruction, installations, and repairs and may also include demolition work. Establishments primarily engaged in the preparation of sites for new construction and establishments primarily engaged in subdividing land for sale as building sites also are included in this sector.
Activities of these establishments generally are managed at a fixed place of business, but they usually occur at multiple project sites. Production responsibilities for establishments in this sector are usually specified in (1) prime contracts or (2) contracts with other construction establishments (subcontracts).
Building Systems
There are essentially six types of construction. These include (1) wood frame, (2) light gauge steel frame, (3) joisted or load-bearing masonry, (4) steel frame, (5) concrete frame, and (6) pre-engineered construction.
Wood Frame Construction
Wood frame construction is probably the oldest and most widely used type of construction in the world. Years ago, man learned that wood was a natural medium to work with. It is plentiful, easy to work, and renewable. Structures are built from standard lumber or timbers, which make up the studs, plates, joists, and rafters. Each piece can be carried by hand and is easily cut and framed on site. Interior walls are easily sheathed with drywall, paneling, or other materials.
With that most residential construction has and still is done with wood, but with a major change in how building exteriors are finished out. In the earliest years wood was also used on the exterior walls and roofs. Wood shingles have almost been replaced by non-flammable materials, such as composite shingles, tile, and metal panels. Exterior walls are commonly covered with brick, stone, and non-wood siding. Such materials are more fire-resistant than wood.
Light Gauge Steel Construction
Light gauge steel construction is similar to wood frame construction in that studs, plates, joists, and rafters are also used in building structures. As you would assume from the heading, these are made from light gauge steel, instead of wood. The steel members most commonly come in a c-shaped cross-section, although s-shaped cross sections are available. Heavier material is used in structural pieces than in non-load-bearing members. The materials are protected by a galvanized coating. Like wood construction techniques, light gauge steel construction allows for ease in carrying materials, as well as cutting and erecting on site.
Whereas wood construction usually utilizes hand-held circular saws, hammers (or nail guns), and nails, light gauge steel construction utilizes metal cutting tools, screw guns, and screws. Light gauge steel construction is commonly used in commercial buildings. Electric miter saws may also be used for metal studs resulting in very high noise levels. Although light gauge steel construction is not as common as wood frame construction in residential work, it is gaining popularity.
Joisted or Load Bearing Masonry Construction
Joisted or load-bearing masonry construct involves utilizing concrete blocks or bricks to build the load-bearing walls. This type of construction may be more vulnerable to seismic stress than other types of structures. Consideration must be given to construction materials and methods to increase the stability of these structures in areas that are prone to earthquakes if used.
In this method of construction, the load-bearing walls are made of brick or formed blocks. The floors and ceilings are constructed with wooden joists, thus the joisted masonry term. This technique is labor-intensive, as each brick or block must be handset.
Steel Frame Construction
Steel frame construction is used primarily in large buildings. The structure is built from steel columns and steel trusses to support floors and roofs. High-rise buildings are commonly built using this method, as it’s easy to transport materials up using cranes and the components are quickly bolted or welded together.
Steel is readily available and construction members are standard, having been extensively engineered for standard column loads and spans. The main structure is built using heavy steel and the non-support structure is usually made from light gauge steel components. Steel is flexible, which is positive in earthquake-prone areas, or in areas of high wind. Steel can flex quite a bit without taking on permanent deformation, making it a great material for constructing tall buildings and bridges.
Concrete Frame Construction
Whereas other methods use wood or steel for the framing, concrete frame construction uses reinforced concrete columns, concrete beams, and concrete slabs to build the support structure. This construction type is often used in high-rise buildings, parking garages, and elevated roadways.
Reinforced concrete has been engineered for years, allowing for its ready use in construction. It employs a large number of laborers, carpenters, and cement finishers who build the concrete forms into which concrete is formed and finished once poured. The roadway system uses numerous precast beams but still requires that columns and slabs be cast on-site using concrete forms built by carpenters. In building construction most all components are cast on-site. Concrete frame construction also presents some concerns with regard to earthquakes, although it does weather wind effect and weather well, over time.
Pre-engineered Construction
The best thing about pre-engineered buildings is how quickly they go up. All of the parts are ready to be bolted and screwed together. This construction type is not limited to shops, garages, sheds, and hangers. Once it is ordered and delivered, then a contractor must erect it. However, large building components must be delivered on-site in flat-bed trucks and manipulated into position using cranes. The size and weight of building components pose ergonomic and safety challenges.
Construction Contractors
The Bureau of Labor Statistics classifies construction into three broad types : (1) building construction by general contractors or by operative builders; (2) heavy construction other than building by general contractors and special trade contractors; and (3) construction activity by other special trade contractors. Special trade contractors include plumbing, painting, and electrical work trades who may work for general contractors under subcontract or directly for property owners. General contractors usually assume responsibility for an entire construction project but may also subcontract all of the actual construction work to other contractors or those portions of the project that require special skills or equipment. General contractors thus may or may not have construction workers on their payroll.
Building construction by general contractors (SIC Code 15) are mainly engaged in the construction of dwellings, office buildings, stores, commercial buildings, and other building construction projects. Operative builders who build on their own accounts for resale are also included in this section.
General contractors and special trade contractors for heavy construction other than building (SIC Code 16) are primarily engaged in the construction of highways; pipelines, communications and power lines, and sewer and water mains; and other heavy construction projects. Special trade contractors are classified in heavy construction if they are primarily engaged in activities such as grading for highway and airport runways; guardrail construction; installation of highway signs; asphalt and concrete construction of roads, highways, streets, public sidewalks; trenching; cable laying; conduit construction; underwater rock removal; pipeline wrapping; or land clearing and leveling.
The general contractor is the manager for any building or renovation project. They’re the ones in charge of hiring all the suppliers and specialists (a.k.a. subcontractors) to get the job done. If they hire employees directly, they often hire carpenters, laborers, and operating engineers who are the first ones on the job to lay out the foundation or they may hire ironworkers to build the steel frame.
Special trade contractors (SIC Code 17) undertake activities of a type that are either specialized in building construction or may be undertaken for building or nonbuilding projects. These activities include painting (including bridge painting and traffic lane painting) and electrical work (including work on bridges, power lines, and power plants).
Establishments primarily engaged in managing construction projects for others on a contract or fee basis, but assuming no responsibility for completion of the construction project, are classified in Services, Industry 8741. Establishments primarily engaged in renting construction equipment, with or without an operator, are classified in Services, Industry Group 735.
Force account construction is construction work performed by an establishment primarily engaged in some business other than construction, for its own account and use, and by employees of the establishment. This activity is not included in this section but is classified according to the primary activity which is or will be performed in the establishment. However, construction work performed as the primary activity of a separate establishment of an enterprise for the enterprise's own account is included in this section.
Installation of prefabricated building equipment and materials by general and special trade contractors is classified in this section. Similar installation work performed as a service incidental to sale by employees of an establishment manufacturing or selling prefabricated equipment and materials is classified according to the primary activity in the Manufacturing or Trade Divisions.
Establishments primarily engaged in the distribution and construction or installation of equipment often present classification problems. Since value-added is not available for distinguishing the relative importance of sales versus installation or construction activities, payroll or employment may be used as measures yielding approximately the same results.
Construction Trades
There are approximately 30 construction trades with laborers, carpenters, electricians, painters and paperhangers, and plumbers and pipefitters making up the highest percentage of the workforce. A complete list of trades is listed in Table 1. Within trades there are sub-specialties.
For instance, carpenters are thought of as the general woodworkers of a building project. But depending on the job, they may be form carpenters, house framers, finish carpenters, or specialize in scaffold construction. Electricians wire up the building. But beyond the general electrical systems like lighting and outlets, there are specialized categories for electrical contractors, including cable work, fire alarm systems, and even sound equipment. They also work in powerplant construction and on turn-around/maintenance projects. Drywallers (often a carpentry specialty) put up the interior walls usually made of gypsum) but “tapers”, another specialty, go behind the drywaller and apply drywall tape with joint compound and sand it down so it is ready to paint.
Excavators are hired by the general contractor when clearing the land for new construction or when tacking on a new addition. The excavator works with heavy machinery to clear the land in preparation for laying a foundation. Sometimes demolition workers (often laborers) are needed to tear down existing construction to make way for changes interior and exterior to the property. The general contractor will pick the specialty needed for the job.
Plastering a wall is a more labor-intensive and time-intensive process than drywalling, and thus there are plastering subcontractors who specialize in the technique. After interior walls go up, the general contractor will either hire a painter to get some color on them or hire a wallpaper specialist to install the covering to ensure a smooth application.
Central heating and air-conditioning are one of the blessings for all new construction, (HVAC) contractors may employ sheet metal workers to install ductwork and/or HVAC mechanics who specialize in installing, repairing, and maintaining everything from the furnace to connecting ductwork.
Masons can be hired to lay brick or install stonework. Tile-setters install everything from mosaics backsplashes in kitchens to terrazzo or marble-tile floors. Other than tiled floors, flooring installers can help install hardwood, wood, or vinyl laminates and carpeting. Glaziers install windows and glass used as cladding in “curtain walls” – non-structural exterior walls which support their own weight and protect from weather.
Roofing might not be the first thing to come to mind during construction, but roofing is an important part of new construction and has a limited life so needs to be replaced over the life of a building. Built-up roofing systems utilize hot kettles with petroleum asphalt or coal tar pitch which may generate significant levels of asphalt or volatile coal tar pitch fumes.[3] Or single-ply roofing systems may be used which involve use of spray adhesives that contain isocyanates.
The following table represents only the potential occupational health concerns related to the construction industry based on the type of construction, job task or work activity, and any related OSHA standards for regulatory compliance. It is limited by the number of OSHA inspections done on a particular hazard involving a particular trade. Given the transient nature of construction, the number of contractors on any given job, and the prevalence of safety hazards, health hazards may be missed. In addition, work may often occur in difficult to reach or observe places such as inside boilers or inside of chiller units.
The information presented herein does not indicate or suggest a relative risk of exposure based on the location within the table nor provides any measurable exposure information. Exposure risk varies depending on the duration and frequency of the work task. Ergonomic hazards will vary depending on the equipment or tool being used, weight of materials, posture, and repetitiveness of the work tasks, and force being used to perform a given task.
Health risks associated with fatigue, working long hours, stress living away from home, and other psychosocial disorders are not addressed. The focus of this information is to provide guidance to understand the occupational health hazards from chemical substances, physical and biological agents, radiological, ergonomic, and environmental hazards from exposure to plants and animals.
Construction Health Hazards
The potential occupational health exposures in this industry were derived from the OSHA Integrated Management Information System database between 1984 to 2020. OSHA reported that out of 64 construction companies surveyed (2014-2018) 79% of the air samples collected for lead were above the OSHA PEL of 50 µg/m3 or air for an 8-hour time-weighted average. https://www.osha.gov/SLTC/lead/industrysector_profile.html Besides, inorganic lead, asbestos airborne contamination, and occupational noise were most frequently cited by OSHA on construction sites.
It should be noted that historically, OSHA health standards have lagged in construction. The permissible exposure limit (PEL) for lead was four times higher in construction than in general industry for approximately 15 years until the Lead in Construction standard was promulgated in 1993. And the PEL used for respirable quartz in construction was so outdated until the OSHA Silica Standards went into effect in 2016 it was based on obsolete air monitoring technology. OSHA inspections in construction in the earlier years of OSHA were by default viewed as the domain of safety compliance officers. Therefore, the hazards presented are not a complete list. In limited cases, we have added some references to NIOSH reports, and we encourage the users of these profiles to research other sources on construction health hazards which will provide a broader view of the full array of health hazards in construction.
It should also be noted that construction workers often do a great deal of industrial rehabilitation and maintenance work which puts them to work in refineries, power plants, and other facilities which present their own workplace hazards. Exposures associated with these workplaces often go unmeasured. These considerations should be kept in mind as limitations to the profiles presented.
NOTES: Welding fumes contain a variety of hazardous chemical substances depending on the base metal, the electrode or filler metal, and the type of welding being done. Similarly, solvent vapors also vary depending on the product and manufacturer. Therefore, it is important to read product labels and Safety Data Sheets for more information. Under the OSHA Hazard Communication and Global Harmonization Standard, Certified Industrial Hygienists (CIHs) can obtain trade secret or classified information in any case whereby workers may be exposed to a hazardous chemical substance and/or their occupational health may be in jeopardy. In order to obtain such classified trade secret information, CIHs may agree to a confidentiality agreement with the manufacturer, distributor, or supplier.
Construction workers are exposed to a wide variety of health hazards on the job.[4] Exposure differs from trade to trade, from job to job, by the day, even by the hour. Exposure to any one hazard may be intermittent and of short duration but is likely to reoccur. A worker may not only encounter the primary hazards of his or her own job but may also be exposed as a bystander to hazards produced by those who work nearby or upwind. This pattern of exposure is a consequence of having many employers with jobs of relatively short duration and working alongside workers in other trades that generate other hazards. The severity of each hazard depends on the concentration and duration of exposure for that job.
Each trade listed in the table below indicates some of the primary hazards to which a worker in that trade might be exposed. Exposure may occur to either supervisor or to wage earners. Hazards that are common to nearly all construction work are heat and in colder climates cold stress, risk factors for musculoskeletal disorders from manual material handling, hand-arm segmental vibration, awkward postures, and repetitive motion.
Chemical hazards are often airborne and can appear as dusts, fumes, mists, vapors, or gases; thus, exposure usually occurs by inhalation, although some airborne hazards may settle on and be absorbed through the intact skin (e.g., pesticides and some organic solvents). Chemical hazards also occur in liquid or semi-liquid state (e.g., glues or adhesives, tar) or as powders (e.g., dry cement). Skin contact with chemicals in this state can occur in addition to possible inhalation of the vapor resulting in systemic poisoning or contact dermatitis. Chemicals might also be ingested with food or water or by touching cigarettes for smokers.
Sanitation is often lacking in construction, making hand-washing difficult and increasing the risk of accidental ingestion.
Elevated risk of exposure and illness or cases have been seen in several construction trades, among them:
- Silicosis among sand blasters, tunnel builders, tuckpointers, and rock drill operators; silica is a pervasive hazard in construction but especially so for painters, bricklayers and allied trades, tuckpointers, laborers, tunnel workers, and operating engineers[5]
- Asbestosis (and other diseases) among insulation workers, steam/pipe fitters, building demolition workers, and others; all construction workers may be potentially exposed during renovation work in buildings containing friable asbestos.
- Lung cancer/Bronchitis among welders and exposure; exposed to hexavalent chromium during stainless steel welding.
- Contact dermatitis among masons and others who work with cement, and
- Parkinsonism and manganese exposure among welders.[6]
- Neurologic disorders among painters and others exposed to organic solvents and inorganic lead from painted building structures to name a few.
Physical hazards are present in every construction project. These hazards include noise, heat and cold temperature extremes, ionizing and non-ionizing radiation, hand-arm and whole-body vibration, and barometric pressure in underwater or subterranean work. Construction work often must be done in extreme heat or cold, in windy, rainy, snowy, or foggy weather, or at night. Ionizing and non-ionizing radiation is encountered, as are extremes of barometric pressure.
Heavy machinery, use of power tools (both electrical and air-powered), and even use of hand tools like hammers create a very noisy work environment. Sources of noise are numerous: vehicles, air compressors, cranes, backup signals, rivet guns, drill motors. nail guns, paint guns, pneumatic hammers, power saws, sanders, routers, planers, explosives, and many more. Noise is present on demolition projects by the very activity of demolition. It affects not only the person operating a noise-making machine, but all those close by and not only causes noise-induced hearing loss but also masks other sounds that are important for communication and for safety. Pneumatic hammers, many hand tools, and earth-moving, and other large mobile machines also subject workers to segmental and whole-body vibration.
Heat and cold hazards arise primarily because a large portion of construction work is conducted while exposed to the weather, the principal source of heat and cold hazards. Roofers are exposed to the sun, often with no protection, and often must heat pots of tar, thus receiving both heavy radiant and convective heat loads in addition to metabolic heat from physical labor. Heavy equipment operators may sit beside a hot engine and work in an enclosed cab with windows and without ventilation. Those that work in an open cab with no roof have no protection from the sun. Workers in protective gear, such as that needed for removal of hazardous waste, may generate metabolic heat from hard physical labor and get little relief since they may be in an air-tight suit. A shortage of potable water or shade contributes to heat stress as well. Construction workers also may work in especially cold conditions during the winter, with the danger of frostbite and hypothermia and the risk of slipping on ice.
The principal sources of non-ionizing ultraviolet (UV) radiation are the sun and electric arc welding. Exposure to ionizing radiation is less common but can occur with x-ray inspection of welds, for example, or it may occur with instruments such as flow meters that use radioactive isotopes. Lasers are commonly used for survey/lay-out work and when installing ceiling tiles. These may pose an eye injury risk if not used correctly.
Those who work underwater or in pressurized tunnels, in caissons, or as divers are exposed to high barometric pressure. Such workers are at risk of developing a variety of conditions associated with high pressure: decompression sickness, inert gas narcosis, aseptic bone necrosis, and other disorders.
Strains and sprains are among the most common injuries among construction workers. These, and many chronically disabling musculoskeletal disorders (such as tendinitis, carpal tunnel syndrome, and low-back pain) occur as a result of either traumatic injury, repetitive forceful movements, awkward postures, or overexertion. Falls due to unstable footing, unguarded holes, and slips off scaffolding and ladders are very common.
Biological hazards are presented by exposure to infectious micro-organisms, toxic substances of biological origin, or animal attacks. Excavation workers, for example, can develop histoplasmosis, an infection of the lung caused by a common soil fungus. Since there is constant change in the composition of the labor force on any one project, individual workers come in contact with other workers and, as a consequence, may become infected with contagious diseases—influenza or tuberculosis, for example. Workers may also be at risk of malaria, yellow fever, or Lyme disease if work is conducted in areas where these organisms and their insect vectors are prevalent. Plumbers and pipefitters who work with heating, ventilation and cooling (HVAC) equipment such as cooling towers may be exposed to legionella bacteria.
Toxic substances of plant origin come from poison ivy, poison oak, poison sumac, and nettles, all of which can cause skin eruptions. Some wood dusts are carcinogenic, and some (e.g., western red cedar) are allergenic. Attacks by animals are rare but may occur whenever a construction project disturbs them or encroaches on their habitat. This could include wasps, hornets, fire ants, snakes, and many others. Underwater workers may be at risk from attack by sharks or other fish.
For a detailed description of the various construction, trades refer to Chapter 7 of the 3rd Edition of The AIHA Occupational Environment – Its Evaluation, Control and Management.
Table 1: Selected Workers by occupational classification and distribution in construction, 2015 (16 years and older)[7]
Label |
Description |
Number (thousands) |
Percent |
Laborer |
Construction laborer |
1,611 |
16.2% |
Carpenter |
Carpenter |
1,134 |
11.4% |
Electrician |
Electrician |
560 |
5.6% |
Painter |
Painter and paperhanger |
524 |
5.3% |
Plumber |
Pipelayer, plumber, pipefitter, and steamfitter |
462 |
4.7% |
Heat A/C mech |
Heating, air conditioning, and refrigeration mechanic |
301 |
3.0% |
Operating engineer |
Operating engineer and other construction equipment operator |
252 |
2.5% |
Repairer |
Installation, maintenance, and repair worker |
232 |
2.3% |
Roofer |
Roofer |
213 |
2.1% |
Truck driver |
Driver/sales worker and truck driver |
165 |
1.7% |
Brickmason |
Brickmason, blockmason, and stonemason |
162 |
1.6% |
Drywall |
Drywall installer, and ceiling tile installer |
154 |
1.6% |
Carpet and tile |
Carpet, floor, and tile installer and finisher |
131 |
1.3% |
Welder |
Welding, soldering, and brazing worker |
91 |
0.9% |
Highway maint |
Highway maintenance worker |
88 |
0.9% |
Material moving |
Transportation and material moving |
60 |
0.6% |
Concrete |
Cement mason, concrete finisher, and terrazzo worker |
49 |
0.5% |
Ironworker |
Structural iron and steel worker |
48 |
0.5% |
Helper |
Construction helper |
45 |
0.5% |
Insulation |
Insulation worker |
42 |
0.4% |
Sheet metal |
Sheet metal worker |
41 |
0.4% |
Fence erector |
Fence erector |
40 |
0.4% |
Misc worker |
Miscellaneous construction and related worker |
36 |
0.4% |
Glazier |
Glazier |
29* |
0.3% |
Plasterer |
Plasterer and stucco mason |
28* |
0.3% |
Dredge |
Dredge, excavating, and loading machine operator |
26* |
0.3% |
Driller |
Earth driller, except oil and gas |
21* |
0.2% |
Power-line installer |
Electrical power-line installer and repairer |
16* |
0.2% |
Elevator |
Elevator installer and repairer |
15* |
0.2% |
Paving |
Paving, surfacing, and tamping equipment operator |
14* |
0.1% |
Iron reinforcement |
Iron reinforcement |
9* |
0.1% |
Boilermaker |
Boilermaker |
8* |
0.1% |
Other |
Farming/fishing/forestry, hazardous material removal, etc. |
32 |
0.3% |
TOTAL |
9,938 |
100.0% |
References
[1] The Center for Construction Research and Training (CPWR) Chart Book, Eighteenth Edition. (2018), Silver Spring MD.
[B] Bureau of Labor Statistics, accessed on September 26, 2021.
[3] John B. Moran Column Editor, Pam Susi & Scott Schneider (1995) Construction Chemical Exposures on a New Construction Site, Applied Occupational and Environmental Hygiene, 10:2, 100-103, DOI: 10.1080/1047322X.1995.10389289
[4] Dave K. Verma, Lawrence A. Kurtz, Dru Sahai & Murray M. Finkelstein (2003) Current Chemical Exposures Among Ontario Construction Workers, Applied Occupational and Environmental Hygiene, 18:12, 1031-1047, DOI: 10.1080/714044193
[5] Charles Beaudry, Jérôme Lavoué, Jean-François Sauvé, Denis Bégin, Mounia Senhaji Rhazi, Guy Perrault, Chantal Dion, Michel Gérin. (2013) Occupational Exposure to Silica in Construction Workers: A Literature-Based Exposure Database. Journal of Occupational and Environmental Hygiene 10:2, pages 71-77.
[6] Michael R. Flynn, Pam Susi. (2009) Manganese, Iron, and Total Particulate Exposures to Welders. Journal of Occupational and Environmental Hygiene 7:2, pages 115-126.
[7] Adapted from CPWR Construction Chart Book (6th edition). Silver Spring, MD. (2018)
The photos were provided by the Construction Safety Council, Hillside, Illinois. They represent some occupational health hazards associated with work activities in the construction industry. Work in construction varies by project and duration and frequency of exposures to the air contaminants.
Worker Exposure Profiles in Construction
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