HPV is a virus that causes warts, not an STI.

Chlamydia is the most common STI in the United States, with an estimated 1.3 million new cases each year.

Being in a monogamous relationship is not a risk factor for STIs, as long as both partners are STI-free.

Abstinence, using condoms, and getting vaccinated are all effective ways to prevent STIs.

Swollen lymph nodes are not a symptom of an STI.

Air pollution is the most common environmental health hazard, and it is responsible for an estimated 7 million deaths each year.

Trees are not a source of air pollution.

Air pollution can cause heart disease, stroke, lung cancer, and a variety of other health problems.

Burning wood in your fireplace is a major source of air pollution.

Radon is the most common environmental health hazard in the home, and it is responsible for an estimated 21,000 deaths each year.

Sunlight is not a source of radon.

Radon is the leading cause of lung cancer in nonsmokers.

Using an air purifier will not reduce radon levels in your home.

Noise is the most common environmental health hazard in the workplace, and it can cause hearing loss, tinnitus, and other health problems.

Birds are not a source of noise pollution.

Noise pollution can cause hearing loss, tinnitus, stress, and a variety of other health problems.

Playing music will not reduce noise pollution in your workplace.