Course 150 - Physical Health Hazards in Construction

Risk Factors and Hazards

risk factors

Risk Factors in Construction

Construction work is dynamic, diverse, and constantly changing. This leads to a great challenge in protecting the health and safety of construction workers. Workers are at risk of exposure to many different types of hazards that can result in physical injury, illness, disability, or even death.

Exposure to physical health hazards (cold/heat stress, noise, fibers/toxins, asbestos, etc.) is the most common risk factor on the worksite. Below is a list of other factors that increase the risk of worker injuries and illnesses while working on construction sites:

  • constantly changing job site conditions
  • poor communications, coordination, and cooperation among contractors
  • lack of skilled workers and high turnover
  • multiple work activities that happen simultaneously
  • failure of subcontractors to meet contract obligations
  • physical violence on the worksite

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1. What is the most common physical health risk factor on the construction worksite?

a. Diversity of work activities
b. Lack of skilled workers and high turnover
c. Failure of subcontractors to meet contract obligations
d. Exposure to physical health hazards such as asbestos

Construction Physical Health Hazard Examples

The table below takes a closer look at common health hazards in the construction industry.

Occupations Potential Health Hazards
Brick masons cement dermatitis, awkward postures, and heavy loads
Drywall installers awkward postures, plaster dust, and heavy loads
Electricians heavy metals in solder fumes, awkward postures, heavy loads, and asbestos
Painters solvent vapors, toxic metals in pigments, and paint additives
Carpet layers knee trauma, awkward postures, glue and glue vapor
Insulation workers asbestos, synthetic fibers, and awkward postures
Roofers roofing tar and heat
Carpenters noise, awkward postures, and repetitive motion
Drillers (earth and rock) silica dust, whole-body vibration, noise
Excavating/loading machine operators silica dust, whole-body vibration, heat stress, and noise
Hazardous waste workers heat stress and toxic chemicals

2. Which of the following occupations has an increased risk of exposure to asbestos?

a. Electricians
b. Carpenters
c. Painters
d. Brick masons

Chemical Hazards

Chemicals are found in many products used at construction sites. Workers may be exposed to dangerous chemicals during construction activities. These include asbestos, lead, silica, carbon monoxide and spray paints. The chemicals can exist in several forms, including:

  • dusts, fumes, and fibers (solids);
  • liquids and mists; and
  • gases and vapors.

These chemicals can enter the body in a variety of different ways. Let's take a closer look.

Inhalation (breathed in) - Inhalation is generally the most common way chemicals can enter the body in a work situation.

Ingestion - accidental swallowing through eating, drinking, or smoking.

Absorption - absorbed through contact with skin or eyes.

Injection - a chemical enters the body when the skin is punctured.

Check out this short audio clip by Dan Clark of Cement burns and irritations are the #1 occupational skin disease in the U.S. Why is wet cement such a widespread danger? How do workers avoid it? Listen!

3. What is the most common way a hazardous chemical can enter the body in a work situation?

a. Ingestion
b. Absorption
c. Inhalation
d. Injection

Health Effects from Chemical Exposure

Effects on health from chemical exposure

There are two types of health effects from chemical exposure.

  • acute
  • chronic

Note: Some chemicals have both acute and chronic effects, such as carbon monoxide.

Acute Effects

These types of effects occur immediately or within a short time (minutes or hours) following exposure. Death is possible from some hazardous substances. Exposure to the chemical is typically sudden, short-term, and with a high concentration. For example, if a worker is exposed to carbon monoxide, they may quickly experience a headache, collapse, or even death.

Chronic Effects

Chronic effects usually develop after continual or repeated exposure to a dangerous chemical. This long-term exposure can sometimes occur over several years. For example, a worker could develop lung cancer from long-term exposure to asbestos.

4. Which type of health effect occurs immediately or within a short period of time?

a. Proximal
b. Terminal
c. Chronic
d. Acute

Asbestos Exposure

Impact of Asbestos.

Construction workers may be exposed to asbestos during demolition or remodeling of older buildings built before 1980. Most of these buildings contain asbestos insulation, or other asbestos containing products.

Asbestos is well-recognized as a health hazard and is highly regulated. Although asbestos is no longer used as an insulation material, workers may still be exposed to asbestos during demolition or remodeling jobs.

Asbestos may also still be found in some taping compounds, asbestos cement, pipes, and floor tiles. Vinyl asbestos floor tiles may be as much as 15% to 20% asbestos, which is released when old flooring is removed.


Asbestos removal can only be done by specially trained asbestos workers. Significant exposure to asbestos can cause breathing problems, lung cancer, and cancer of the lung lining many years after exposure.

Check out this short audio clip by Dan Clark of that talks about the hazards and solutions related to asbestos exposure.

5. When are workers most likely to encounter exposure to asbestos?

a. During excavation activities
b. During demolition or remodeling pre-1980 structures
c. While replacing insulation after water damage
d. After damage due to wind storms or tornadoes

Welding Fumes


Welding fumes contain a variety of chemicals depending on what is being welded on, chemical makeup of welding rods, fluxes and shielding gases. Workers in the area who experience the symptoms listed below should leave the area immediately, seek fresh air and obtain medical attention.

  • Acute exposure to welding fumes and gases can result in eye, nose and throat irritation, dizziness, and nausea.
  • Prolonged exposure to welding fumes may cause long-term effects such as lung damage and various types of cancer, including lung, larynx, and urinary tract.

Health effects from certain fumes may include metal fume fever, stomach ulcers, kidney damage and nervous system damage. Prolonged exposure to manganese fumes can cause Parkinson's–like symptoms.

Gases such as helium, argon, and carbon dioxide displace oxygen in the air and can lead to suffocation, particularly when welding in confined or enclosed spaces. Carbon monoxide gas can form, posing a serious asphyxiation hazard.

6. What is the long-term danger from prolonged exposure to welding fumes?

a. Irritability and disorientation
b. Temporary dizziness and nausea
c. Injury to the eyes due to radiation
d. Lung damage and cancer

Next Section


A variety of solvents with varying degrees of toxicity are used in construction. They are in paints, glues, epoxies and other products. Health hazards associated with solvent exposure include:

  • toxicity to the nervous system,
  • reproductive damage,
  • liver and kidney damage,
  • respiratory impairment, cancer, and
  • dermatitis.

Generally, the possibility of exposure to excessive amounts of solvent vapors is greater when solvents are handled in enclosed or confined spaces.


Symptoms of overexposure to solvents include:

  • irritate your eyes, nose or throat;
  • make you dizzy, sleepy, give you a headache or cause you to pass out;
  • affect your judgment or coordination;
  • cause internal damage to your body; and
  • dry out or irritate your skin.

7. Which of the following would be a symptom of overexposure to solvents?

a. Dizziness, headache, and loss of consciousness
b. Nervousness and inattention to detail
c. Coughing spasms and extreme mucous production
d. Irritability and mood swings


Respirable Crystalline Silica Compliance Introduction

About 2.3 million workers are exposed to respirable crystalline silica in their workplaces, including 2 million construction workers who drill, cut, crush, or grind silica-containing materials such as concrete and stone, and 300,000 workers in general industry operations such as brick manufacturing, foundries, and hydraulic fracturing, also known as fracking.

Quartz is the most common form of crystalline silica. In fact, it is the second most common surface material accounting for almost 12% by volume of the earth's crust. Quartz is present in many materials in the construction industry, such as brick and mortar, concrete, slate, dimensional stone (granite, sandstone), stone aggregate, tile, and sand used for blasting. Other construction materials that contain crystalline silica are asphalt filler, roofing granules, plastic composites, soils, and to a lesser extent, some wallboard joint compounds, paint, plaster, caulking and putty.

Exposure to excessive silica dust causes lung scarring and disease over time. The size of the airborne silica particles determines the amount of risk. Smaller particles can be inhaled deep into the lungs where they can cause damage. Larger particles, such as beach sand, are not as great a concern because they are too large to inhale.

Compressed Air
brick cutting
Brick Cutting
concrete cutting
Concrete Cutting

Check out this short audio clip byDan Clark of Silica dust is common in worksites, can scar the lungs and cause cancer. Symptoms sometimes don't appear for 10 years.

8. Since the primary route of exposure to airborne silica is inhalation, what determines the amount of risk of exposure?

a. The amount of silica in the air
b. The toxicity of the particular type of silica
c. The duration of exposure to silica particles
d. The size of the silica particles



Lead is very toxic and can cause several long-term health problems. Construction workers can be exposed to lead on bridge repair work, lead paint removal on metal structures or buildings or demolition of old buildings with lead paint, or using lead solder.

The frequency and severity of medical symptoms increases with the concentration of lead in the blood. Common symptoms of acute lead poisoning are:

  • loss of appetite
  • nausea
  • vomiting
  • stomach cramps
  • constipation
  • difficulty in sleeping
  • fatigue
  • moodiness
  • headache
  • joint or muscle aches
  • anemia

Acute health poisoning from uncontrolled occupational exposures has resulted in fatalities. Chronic overexposure to lead may result in severe damage to the central nervous system and reproductive systems.

Check out this short audio clip by Dan Clark of that talks about lead hazards and exposure.

9. Chronic overexposure to lead may result in _____?

a. damage to the central nervous system
b. damage to the arterial circulatory system
c. lung congestion and cancer
d. long-term dementia and ALS
confined space

Confined Spaces

Confined spaces include manholes, sewers, vaults, tanks, and boilers in new construction or in repair and maintenance work. Exposure to chemicals or lack of oxygen in confined spaces can be deadly. Airborne chemicals can quickly reach dangerous levels in confined spaces that are not ventilated. Typical hazardous atmospheres within confined spaces include:

  • lack of oxygen,
  • carbon monoxide,
  • hydrogen sulfide,
  • welding fumes, and
  • solvent vapors.

Oxygen deficiency is especially dangerous as it is typically not noticed until it's too late: the person entering a confined space may instantly collapse.

For more information on confined spaces in general industry, see course 713, Confined Space Program, and course 816, Confined Space Safety in Construction.

10. Why is oxygen deficiency so dangerous in confined spaces?

a. It can inadvertently cause a fire or explosion
b. It's too late before you realize there's no oxygen
c. Low oxygen may result in higher carbon dioxide levels
d. Oxygen deficiency is very common in all confined spaces

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