Script for the Environmental and Occupational Health History

Script for The Environmental and Occupational Health History:

A Practical Guide for the Health Care Provider Course

Welcome to this online training course, The Environmental and Occupational Health History: A Practical Guide for the Health Care Provider Course. This course has been designed to help you meet your continuing education requirements. To continue, press the next button at the bottom.

Introduction

Health problems caused by environmental and occupational exposures look just like any other health problem. Exposures to hazardous substances in the environment account for an estimated 24% of the global disease burden and 23% of all deaths.

My name is Dr. Robert Harrison and I am a physician specializing in Occupational and Environmental Medicine. I'm so glad you're tuning in for this training because understanding the environment your patients live and work in is critical to effectively treat illness.

The Toxic Avenger, MD, my superhero alter ego, will guide you through this course. If you leave the course at any time, the course will prompt you back to the place where you left off when you return. To enhance your understanding of the material in this course, we highly recommend you turn on the audio.

Objectives

After completing this course, health care providers will be able to:

•Explain why environmental and occupational exposures may be important to the health of their patients.

•Identify hazardous substances in the environment and how patients may be exposed to them.

•Describe the health effects of hazardous substances and how such effects might appear in a clinical setting.

Course Overview:

This course is made up of three sections: basic principles, places and environments, and clinical presentation.

The first section, basic principles, will cover the basic principles of taking an environmental and occupational health history. Throughout the course, basic principles slides have a blue border.

The second section, places and environments, will highlight different situations where your patient may be exposed to hazardous substances on the job, at home, or in the community. Places and environments slides have a green border.

The final section, clinical presentation, will review scenarios that you may encounter in the clinic, which can be the result of environmental and occupational exposures to hazardous substances. Clinical presentation slides have an orange border.

Finally, the black boxes at the bottom of the page provide additional resources and materials. These include a printable exposure history form that you can usein your practice, tools to answer challenging questions that patients may ask, and a summary of the main points covered by the course.

You may review the course in order, or skip around between sections, as you prefer. To view the course in order, click the next button below. To find out more about an individual section or resource, click on any shape below. You will be able to return to the course overview screen at any time using the navigation panel at the far left. You will also be returned to the course overview automatically at the end of the course.

Pre-Test Basic Principles

Before we begin the Basic Principles section, we will briefly assess your knowledge of environmental and occupational health.

Please complete the following training questions on your own. Please note that there is no audio for these questions.Click next to continue.

Basic Principles

These are the basic principles of taking an environmental and occupational exposure history. To learn more, click next or any box below.

Three Key Questions

For every patient that you suspect may have an illness with an environmental or occupational cause, ask:

1. What do you do for a living? Do you work with any chemicals at home or in the workplace?

2. Are you ever exposed to potential hazards in your home, community, or workplace?

3. Do you think any of your problems today are caused by exposures in your home, community, or workplace?

•Asking these questions takes less than a minute and can be extremely valuable to help you understand the causes of your patient’s illness.

•If you need to go into more detail with your patient, use this form.

Sources of Exposure

Introduction

Hazardous substances can be absorbed into the body through breathing, ingestion, or skin contact. Possible sources of exposure to hazardous substances and other agents are listed at the left.

Click next, or on any item at left, for an example.

Air

An example of a hazardous substance encountered in air is PM 2.5 (fine particulate matter less than 2.5 micrometers in diameter), which is a result of air pollution. When inhaled by children, PM 2.5 can exacerbate asthma.

Water

An example of a hazardous substance encountered in drinking water is cryptosporidiosis (KRIP-to-spor-id-ee-osis), a disease caused by the Cryptosporidium parvum(KRIP-to-spor-id-ee-um PAR-voom) parasite. The most common symptom from drinking water contaminated by this parasite is diarrhea.

Food

An example of a hazardous substance encountered in food is mercury. In some types of fish like swordfish, mercury levels can be high. The developing fetus is at risk of developmental deficits if exposed to high levels of mercury in utero.

For more information, click on the link.

Soil

An example of a hazardous substance encountered in soil is lead. Lead in soil is frequently a result of contamination from industrial use and can cause developmental deficits in children.

Other

Hazardous substances can also be encountered via cosmetics, toys, and household items. For example, formaldehyde has been found in laminate wood flooring, particle board cabinets, and furniture. In some cases, exposure to formaldehyde can be high enough to cause respiratory and neurological problems, and over time, increased risk for nose and throat cancers.

Types of Exposures

Introduction

Many different substances can cause environmental and occupational health problems. These are listed on the sticky notes here.

Click next; or click on the red x at top right, then click on any sticky note; for more information.

Chemical

Chemical exposures are the most common source of environmental and occupational health problems. There are 80,000 chemicals in common use today and the number is growing. Many of these chemicals have not been tested for acute or chronic health effects. Some of these chemicals are persistent in the environment, such as polychlorinated biphenyls (By-fennels), or PCBs. PCBs are a group of man-made compounds that were widely used in the past, mainly in electrical equipment. PCBs were banned at the end of the 1970s in many countries because of environmental concerns.

Physical

Physical hazards in the environment include falls, drownings, noise, and firearms. Helmets and seat belts can help protect against some of these hazards. Another example of a physical hazard is extreme heat, which may cause heat stress.

Biological

Biological hazards in the environment include infectious diseases and waterborne hazards. Examples include cryptosporidiosis(KRIP-to-spor-id-ee-osis)and hepatitis.

Psychological and Social

Psychological and social hazards in the environment include tensions between co-workers, stress after disasters, and health disparities due to unequal access to care and quality of care.

Radiologic

Radiologic hazards in the environment include unnecessary medical radiation and ultraviolet-B (UV-B) sun exposure.

Toxicology

Hazardous substances are absorbed, metabolized, and excreted.
Most are excreted or eliminated over time.
Some substances persist for many years in bone and fat.

Generally, there is a dose response pattern that results from exposure to hazardous substances.
It is said that “the dose makes the poison”.
Some chemicals may be harmful at very low levels.
For carcinogens, there may be no safe level.

Environmental and occupational injuries and diseases often have non-specific symptoms that can have a variety of causes. Determining the exact cause of your patient’s health problems may not always be possible.

Types of Health Effects

Introduction

There are three types of health effects:

Acute
Subacute
Chronic

Click next or the boxes at left for definitions and examples of each.

Acute Health Effects

Acute health effects occur within minutes or a few days post-exposure. An example of an acute health effect is heat stress.

Heat stress includes conditions of various severity such as the following:

Mild conditions like heat rash and heat cramps
More serious heat exhaustion
Most serious heat stroke, which can cause death or permanent disability without emergency treatment

People who are most sensitive to heat stress include:

The elderly
People with chronic medical conditions
Infants and young children
Outdoor workers (farmers, construction workers, etc.)

Click on the link for more information.

Subacute Health Effects

Subacute health effects occur within several days or months post-exposure.

Examples of subacute health effects are headaches, memory problems, and numbness and tingling of the extremities resulting from exposure to mercury-contaminated skin cream over a period of months.

Click on the link for more information.

Chronic Health Effects

Chronic health effects occur within many months or years post-exposure.

Examples of chronic health effects are aplastic anemia and acute myeloid (MY-eh-loid) leukemia (AML) that may occur in benzene-exposed workers.

Click on the link for more information.

Assessing Exposure

Introduction

Assessing the level of exposure to a hazardous substance is challenging -- among the most difficult you may encounter in your clinical practice.

Click next, or the links below, for more information.

Qualitative Data

To qualitatively assess hazards encountered by a patient, you may ask:

Do you use the material

...directly?

...in a confined space?

...for a long period of time?

...on a regular basis?

Can you talk and hear comfortably at work?

Can you see dust in the air when you look across your work area?

Quantitative Data

Environmental sampling specialists can measure quantitative levels of hazardous chemicals and other substances in air, water, food, soil, the workplace, and other sources/environments. One example of such a specialist is an industrial hygienist.

Laboratory tests can measure levels of some hazardous substances in the body, as well as the body's response to the substance.

Comparative Risk

As a general rule, hazards and potential risks are greater for:

Direct exposures, compared to indirect exposures.
Indoor exposures, compared to outdoor exposures.
Breathing exposures, compared to skin exposures.
Skin exposures, compared to ingestion exposures (for adults).

Often, exposure over months or years is more hazardous than exposure over minutes, days, or weeks. However, there are many instances where even a short duration of exposure can be harmful. For example, an hour's exposure to carbon monoxide can be fatal and a brief splash of acid on the skin can cause serious damage.

Safety Levels

Government agencies set levels of hazardous substances that are allowed in air, water, food, soil, the workplace, and other sources/environments.

For example, U.S. EPA sets safe levels of ozone that are allowed in outdoor air. Above these levels, the incidence of cardiac and respiratory disease may increase in the general population.

In general, safety levels set for environmental exposures are many times lower than those allowed for occupational exposures.

Latency

•Latency is the time between exposure to an agent and when symptoms first become apparent.

•For environmental and occupational exposures, latency may be long or short.

•Latency for solid cancers, such as mesothelioma (meh-zo-THEE-lee-oma), tends to be longer than latency for blood cancers, such as leukemia.

•In Libby, Montana, workers exposed to vermiculite(ver-MICK-u-light) contaminated with asbestos, and their families, developed cancer some 40 years after the exposure.

Sensitive Populations

Introduction

Sensitive populations include:

Children
Women of reproductive age, because of possible harm to the developing fetus or breastfeeding infant
The elderly
People with chronic medical conditions

Click next; or click on red x at top right, then click on any face in the photo; for more information.

Children

Children's bodies are more vulnerable because they are still developing.

Children breathe, eat, and drink more air, food, and water, compared to adults, in proportion to their weight.

Children have an exploratory nature. Young children crawl on the ground and frequently put their hands in their mouths.

Children may be both unaware of risks and unable to make choices to protect their health.

Click on the link for more information.

Women of Childbearing Age

Women of childbearing age are particularly vulnerable to environmental and occupational health hazards.

During pregnancy, hazardous substances may affect the developing fetus.

Some hazardous substances accumulate in breastmilk and can be transferred to the baby via breastfeeding.

Many hazardous substances have long half lives, so they persist in the body for a long time. Such exposures can have harmful effects even if they occur months or a year before pregnancy.

Chronic Medical Conditions

Men and women with chronic medical conditions may be more susceptible to certain infectious, chemical, and other hazardous substances.

For example, people with the conditions listed below are advised by the FDA not to eat raw oysters because of the risk of Vibrio vulnificus (VI-brio vul-NI-fi-cus):

Liver disease
Iron overload disease
Diabetes
Cancer
Stomach disorders
Any illness or medical treatment that weakens the body's immune system, including HIV infection.

The Elderly

Men and women of advanced age are more susceptible to certain infectious agents, heat waves, and other hazardous substances, because of a decreased immune system and the reduced ability of the body to eliminate toxins.

For example, particulate matter in the air can be especially damaging for the elderly. Pollution can exacerbate chronic medical conditions including cardiovascular and respiratory disease.

Click on the link for more information.

Clinical Testing and Biomonitoring

Types of Testing

There are two basic types of laboratory tests that may be relevant when taking an environmental and occupational health history:

Clinical tests measure the body's response to a hazardous substance, such as elevated liver enzyme or impaired neurologic function.

Biomonitoring tests measure the body burden of hazardous substances or their metabolites in blood, urine, or other bodily fluid.

Many of these tests are simple and readily available. However, testing for some substances can be difficult and the protocol varies by substance.

Analytic vs. Clinical Validity

To be useful in clinical practice, a test should be demonstrated to have both analytic and clinical validity.

Analytic validity means that test results are accurate and reliable.
Clinical validity means that test results identify, measure, or predict a patient's clinical status.

Food and Drug Administration (FDA) approval provides assurance that the test has adequate analytic and clinical validation and that it is safe and effective.

Clinical Laboratory Improvement Amendments (CLIA)(KLEE-ah) certification is not sufficient, as CLIA standards address analytic validity but not clinical validity.

Click on the link for more information.

Examples of Useful Tests

To be useful, a test should:

Be targeted at a specific substance, for which there is a reason to suspect exposure,
Be based on clinical signs and symptoms, and
Have measurable levels that can be interpreted and correlated with a health problem or potential health problem.

Examples of Useful Tests:

Blood testing for lead in children and adults who are exposed to lead.

Urine testing for mercury in a symptomatic patient exposed to inorganic forms of mercury (such as occupational exposures).

Examples of Non-Useful Tests

Other tests are available, but their utility in clinical settings is less clear. Types of testing that are generally not useful in the clinic include:

Hair testing
Unvalidated testing (i.e., not FDA approved)

Inappropriate testing will lead to unnecessary abnormal test results that may heighten anxiety and lead to potentially inappropriate treatment.

Resources

Click on any of the links below for more resources.

Pre-Test Questions: Places and Environments

Before we begin the Places and Environments section, we will briefly assess your knowledge of occupational health risks.

In the following slides, match the chemical exposure to the worker(s) likely to be affected, by clicking on the picture of the worker(s). A blue box will appear around the selected worker(s).

Please complete the following training questions on your own. Please note that there is no audio for these questions.Click next to continue.

Places and Environments

•Be aware that your patient may be exposed to hazardous substances through their job, home, and community.

•Children may also be exposed to hazardous substances at daycare and school.

Job

•Many types of jobs can result in exposure to potentially hazardous substances.

Auto-Mechanic Case Study

Introduction

The following case study shows the value of taking a thorough environmental and occupational health history when evaluating a patient with non-specific symptoms.

In this case, the exposure was ultimately found to be occupational in origin.

Clinical Presentation

A 24 year-old male presents with numbness and tingling that began in his hands and feet and then spread to his forearms and waist. After several months with these symptoms, Jim sees a neurologist, who diagnosed him with peripheral neuropathy due to idiopathic autoimmune disease and prescribed steroids.

Occupational and Environmental History

Jim has worked in an auto garage for the past 10 years. A union representative tells Jim that chemicals used by auto mechanics can cause health problems and suggests that Jim go see the Toxic Avenger, MD.