Proper handwashing helps prevent the spread of infections such as diarrhea and pneumonia that are responsible for 3.5 million deaths of children every year. (CBC)

Millions of children around the world will be encouraged to wash their hands with soap on Wednesday to mark the UN's first Global Handwashing Day.

The campaign, to be carried out in part by UNICEF, is designed to send the message that handwashing with soap is an easy and effective way to prevent diarrheal disease and pneumonia.

Sarah Crowe, spokeswoman for UNICEF in South Asia, told CBC News that 76 countries are taking part in the day. The campaign is expected to focus on children with events in schools.

"We're hoping that today, the 15th of October, will be the start of something quite historic when this very ordinary act of washing hands with soap will turn out to be quite extraordinary for millions of children across the world," Crowe said.

Crowe said deaths by diarrhea and pneumonia "can be very easily prevented by the simple act of washing hands with soap."

According to UNICEF, the two illnesses are responsible for 3.5 million deaths of children every year.

The UN General Assembly declared 2008 to be the International Year of Sanitation. The Global Handwashing Day is part of the year and underlines its call for improved sanitation and hygiene practices.

In a news release on Wednesday, UNICEF said children in particular suffer when good sanitation is in short supply and poor hygiene is the norm.

"More than 5,000 children under the age of five die every day as a result of diarrheal diseases, caused in part by unsafe water, lack of access to basic sanitation facilities and poor hygiene," the news release said.

"By washing hands with soap, families and communities can help reduce child morbidity rates from diarrheal diseases by almost 50 per cent."

UNICEF said it hopes on Global Handwashing Day that children will learn the importance of washing their hands with soap and become "agents of change" by taking that message home.

"Handwashing with soap, particularly after using the toilet and before eating, could significantly impact health, survival, child mortality, and help reduce poverty," UNICEF said.

Activities scheduled around the world to mark the day include the release of a song about handwashing that will be performed by the Wiggles, celebrities making public service announcements and simultaneous handwashing events involving children.

The day is being organized by the Public Private Partnership for Handwashing, an initiative spearheaded by UNICEF, the U.S. Agency for International Development, the U.S. Centers for Disease Control and Prevention, the World Bank, Unilever, and Procter and Gamble.