From left, state employee David Wainwright gives identifying information to American Red Cross phlebotomist Chris Culpepper on Wednesday, July 6, 2016 before beginning his blood donation in the NCDENR ground floor hearing room during a four-hour Red Cross blood drive in the Archdale Building on the Legislative mall in Raleigh, N.C. The usual summer shortage of blood donations has prompted the Red Cross to release an emergency call for more blood donations. (Harry Lynch/Raleigh News & Observer/TNS)
From left, state employee David Wainwright gives identifying information to American Red Cross phlebotomist Chris Culpepper on Wednesday, July 6, 2016 before beginning his blood donation in the NCDENR ground floor hearing room during a four-hour Red Cross blood drive in the Archdale Building on the Legislative mall in Raleigh, N.C. The usual summer shortage of blood donations has prompted the Red Cross to release an emergency call for more blood donations. (Harry Lynch/Raleigh News & Observer/TNS) Credit: Harry Lynch

When Corinne Standefer retired as a volunteer from the Lane Bloodworks in Eugene, Ore., last month, she had donated 37 years of her life _ and almost 19 gallons of blood.

The 89-year-old gave her first pint decades ago to help a friend who had cancer.

โ€œWhen they called me and said โ€˜Could you donate again?โ€™ I just started coming in,โ€ she recalled.

So, every eight or nine weeks, as often as itโ€™s allowed, Standefer would roll up a sleeve and become one of the prized older donors who contribute the bulk of the U.S. blood supply. Overall, nearly 60 percent of blood donations come from people over 40 โ€” and nearly 45 percent come from people older than 50, according to the AABB, an international nonprofit focused on transfusion medicine and cellular therapies.

Thereโ€™s a problem with that, though. Like Standefer, many regulars are aging out of the donor pool. Increasingly, blood industry experts say, there are too few young people lining up to replace them.

โ€œThe older generations seemed to have internalized the message that we always have to have an adequate supply of blood on the shelves,โ€ said Dr. James AuBuchon, president and chief executive of Bloodworks Northwest in Seattle. โ€œThe younger generations just seem less wired toward that message.โ€

For people who grew up during World War II โ€” and their children, the baby boomers โ€” blood donation was a civic duty that became a lifelong habit.

โ€œIt was a cultural thing to donate,โ€ said Marie Forrestal, president of the Association of Donor Recruitment Professionals, or ADRP, a division of Americaโ€™s Blood Centers.

That cultural norm has changed, though, and for nearly a decade, blood banks have focused on recruiting teens and young adults, often through high school and college blood drives.

โ€œWeโ€™re trying to capture the people who are 16 and older,โ€ Forrestal said.

The tactic has been successful: Kids in the youngest age groups โ€” 16-18 and 19-22 โ€” now account for about 20 percent of all donations.

But thatโ€™s not enough to compensate for lower turnout among people in their late 20s and 30s who can be harder to reach, more mobile and less inclined to donate than other generations. Fewer than 10 percent of blood donations come from people ages 23-29, with a little more than 12 percent from people in their 30s.

โ€œSometimes we see them come back when life kind of smacks them in their face in their 40s,โ€ Forrestal said.

Even as donor demographics have changed, so has Americaโ€™s thirst for blood. Overall, blood use has dropped by about a third in the past decade, largely because of improvements in surgical technique and a focus on blood conservation, AuBuchon said.

The 13.1 million units of whole blood and red blood cells transfused in 2013 represented a 4.4 percent decline compared with 2011, a recent analysis by the Centers for Disease Control and Prevention showed.

But the dip in donors has fallen faster. Latest figures arenโ€™t out, but AuBuchon, a former AABB president, estimates that about 11 million units of blood were donated last year, down from more than 14.2 million collected in 2013. He estimates the number of donors has dropped from 6.8 million to about 6 million in that time.

โ€œIt is increasingly difficult to keep this smaller amount of blood on the shelf,โ€ AuBuchon said. โ€œThere is considerable concern about the stability of the blood system.โ€

Sporadic shortages often occur now in select areas of the country and at times of historically low donation โ€” summer vacation, winter holidays, flu season. But those shortages could become worse if new donors arenโ€™t found, AuBuchon said.

Blood Donation Basics

Volunteers donated more than 14.2 million units of blood in 2013, according to the latest available figures. More than 13.1 million units were used for transfusions that year.

To Give Blood, Volunteers Must:

Be healthy, with a normal pulse and blood pressure, and a normal temperature.

Meet minimum age requirements in your state, typically 16 years old.

Weigh at least 110 pounds.

Be free of infections that can be transmitted through blood transfusion, or risk factors for the infections.

Not have donated blood in the past 56 days.

Volunteers Are Deferred From Giving Blood For Several Reasons, Including:

Not feeling well on the day of donation.

Past use of needles to take drugs not prescribed by a medical professional.

Being a man whoโ€™s had sex with another man in the past 12 months _ or a woman whoโ€™s had sex with such a man in the past 12 months.

Getting tattooed in the past 12 months, unless it was done under sterile conditions at a state-licensed facility.

Having certain medical conditions or receiving certain medical treatments or medications.

Living or traveling in certain areas of the world for designated periods of time.