World Water Day

Image of Blue deep sea foaming water

Water is one of the planet’s most precious resources. That’s why it’s important to stay aware of the issues surrounding it. World Water Dayexternal icon is observed each year on March 22 to promote the responsible use of water and access to safe water for everyone.

Every day, people use water in many ways—for example, for drinking, agriculture, industry, recreation, hygiene, sanitation, and health care. However, warming temperatures, together with other natural and human-made stressors, have the potential to impact our water on a large scale. This year’s World Water Day theme highlights the link between climate change and water, and the important role people must play to protect our water resources.

Diarrheal Diseases

Changes in temperature have been linked to an increase in many infectious diseases, including diseases that cause diarrhea. Research suggests that increases in temperature due to climate change may increase the risk of diarrheal diseases. In general, diarrheal diseases, such as typhoid fever and cholera, are more common when temperatures are higher. Although rare in the United States, outbreaks of cholera and typhoid continue to occur in low-resource countries. Together, these diseases sicken millions and kill an estimated 257,400 people each year.

The effects of changing temperatures and climate on water sources are not always the same, so patterns may differ by location and type of germ. Places that have extremely high temperatures and little rainfall may experience drought conditions that dry up safer, more protected sources of water. In these situations, people often resort to using unsafe sources that are more likely to contain germs that cause diarrhea. Places that have extremely high rainfall and flooding conditions may also experience contamination of drinking water sources and ground crops—for example, when a latrine overflows. Where there is no sanitation facility that can safely separate waste from human contact, many germs causing diarrheal diseases spread from human waste into drinking water or a community’s food supply.

Water is also important for prevention and treatment strategies to combat these diseases. Safe water is a key part of regular handwashing with soap—one of the most important practices a person can follow to prevent the spread of germs. Furthermore, the foundation of cholera treatment is hydration therapy—a treatment that requires safe water to dissolve sugar and salt, which the patient then drinks to replenish fluids lost through frequent diarrhea.

CDC works to prevent, detect, and respond to infectious disease outbreaks in the United States and around the world and provides technical support in cases of emergencies. In addition, CDC has partnered with the World Health Organization to launch Ending Cholera: The Global Roadmap to 2030external icon, a collaborative approach to cholera prevention and control.

Harmful Algal Blooms

A warming planet can affect water quality in many ways. When temperatures are warmer, algae may grow faster and persist for longer periods of time, especially if waters have a lot of nutrients such as phosphorus and nitrogen. Some types of algae can form toxic blooms (also called harmful algal blooms or HABs). These HABs can harm people, animals, and the surrounding environment. In fact, all 50 states, Puerto Rico, and the U.S. Virgin Islands have reported HABs. As the earth warms, HABs may become more frequent or last longer, resulting in more human and animal illnesses, as well as damage to local environments and economies.

HABs are a One Health issue—they can harm the health of people, animals, and our shared environment. That’s why we use a One Health approach that recognizes the connections between human, animal, and environmental health to track, respond to, and reduce health impacts caused by HABs.

What You Can Do

Everyone can play a role in protecting the planet. Celebrate World Water Day.

World Water Day is also an opportunity to learn about water-related issues that affect us locally. For more information about CDC’s water-related public health efforts in the United States, visit these websites: Drinking Water, Healthy Swimming, and Water, Sanitation, and Hygiene-Related Emergencies.