Goals
Here are the big ideas you will learn about in this lesson:

• Things in your environment (such as food, pollution, and toxic chemicals) can affect your health.
• Many factors influence the potential health effects from exposure to an environmental health hazard.
• You can learn to recognize health hazards in your environment and help reduce your risk.

Frogs are very sensitive to the conditions in their environment. Their skin can easily absorb substances that it touches and their eggs don’t have a hard protective shell. Because of this, they can serve as an indicator species—they can give early warning about harmful changes in environmental conditions. Frog populations may become smaller and some frogs may develop unusual malformations, such as missing eyes, missing or misshapen limbs, or extra limbs.

Scientists study frogs because the environmental factors that affect frogs’ health may also impact other animals in the ecosystem, including humans.

Click "View" on the left to watch a video about how environmental conditions are affecting frogs.

What three environmental factors can cause frog malformations? Write your response, then click "Save Notes."

You do not live in polluted water like some frogs, but you may be exposed to environmental health hazards every day. For example, sunlight has some positive health effects, but too much sunlight can damage skin and increase the risk for skin cancer. It is difficult to say how much exposure is too much, but it is usually a good idea to wear protective clothing, stay in the shade when possible, and use sunscreen.

Many common household products contain hazardous chemicals that can cause a variety of health problems. For example, some cleaning products contain ammonia, which can cause skin, eye, or respiratory irritation. Long-term exposure to dry cleaning chemicals, such as perchloroethylene, can increase your risk for some cancers. You can reduce your exposure to such chemicals by wearing gloves and opening windows when using them, or by choosing a safer alternative product.

List three environmental health hazards that you might come in contact with in your day-to-day life. Describe how you come in contact with each hazard and how you might protect yourself. Be sure to click "Save Notes."

You can be exposed to environmental health hazards in one of three ways: swallowing (ingestion), breathing (respiration), or skin contact (absorption). How dangerous the exposure is can be affected by:

• The way that you are exposed: Touching a sponge containing a toxic cleaning product may not be too big a problem, but accidentally swallowing the same product could be extremely dangerous.
• The amount of the exposure: Being exposed to a larger quantity of a toxic substance can be much more harmful than exposure to a smaller quantity.
• The frequency of the exposure: Being exposed to a toxic substance on a regular basis can be more harmful than a single or rare exposure.
• Your age, your overall health, and your genes: Some people's bodies are better able to deal with exposure to a health hazard. Because fetuses and children are small and still developing, they are particularly vulnerable.

Consider the three health hazards you listed on the previous screen. Describe how the above factors might affect how dangerous your exposure could be. Be sure to click "Save Notes."

While a little contact with a health hazard may not seem like a big deal, even a small amount of exposure can cause problems for some people. In addition, low doses of a toxin can accumulate over a long period of time.

People are often exposed to small amounts of pesticides—chemicals that keep pests, such as weeds and insects, under control. Scientific studies have found that a variety of health problems are associated with pesticide exposure. For example, one pesticide, chlorpyrifos, has been linked to cognitive development problems in children. Other possible harmful health effects from pesticide exposure include skin irritation, breathing difficulties, reproductive problems (such as birth defects or decreased fertility), and increased risk for some types of cancer.

Pesticides are commonly applied to farms, lawns, and gardens, where people can be exposed by touching the ground or plants or by simply breathing. Other sources of exposure include eating fruits and vegetables that have been grown with pesticides, and handling pets that have been treated for fleas and ticks. When all these are added together over time, the amount of exposure can be larger than you realize. Now, click “view” on the left to watch a video about a city that banned the use of pesticides for lawn or garden use.

Where might you be exposed to low levels of pesticides? How might you reduce your exposure to pesticides? Write your response, then click "Save Notes."

It is not always possible to avoid contact with health hazards. However, you can take responsibility for your own health by keeping your exposure to the various health hazards in your environment as low as possible.

Click "View" on the left to watch videos about how to reduce exposure to three common environmental health hazards: pesticides, chemical contaminants, and secondhand smoke.

Choose one of the three health hazards that were featured in the videos. Think about two additional ways that you could reduce your exposure to it. Describe these in the box below. Be sure to click "Save Notes."

You probably know that smoking cigarettes can cause heart disease and lung cancer, along with many other health problems. Passive smoking—inhaling the secondhand smoke from somebody who is smoking—also exposes you to the toxic chemicals contained in cigarettes and puts your health at risk. Did you know that even thirdhand smoke—the residue left behind on furniture and walls after someone has smoked in a room—contains toxins that can harm your health?

On the left are three interactive activities about some of the environmental hazards found in the city, on the farm, and at the coast. Choose the interactive that most closely represents where you live, and click “View” to explore it.

Choose two health hazards from the interactive activity (that you haven’t already written about). How might you be exposed to each hazard? How could you reduce your exposure? Write your responses in the box below. Be sure to click "Save Notes."

In this lesson, you have learned how environmental factors can affect human health. You have explored how people are exposed to health hazards in their environments, and you have investigated how you can take responsibility for your own health and reduce exposure to environmental hazards. You will now complete a final project that shares what you have learned.

Begin by reviewing your notes. Click "review my work" above and view or print out the screen that pops up.

Then, click the How Does Your Environment Affect Your Health?—Final Assignment (PDF) and select one of the three assignments.