TIME toxins

How an Ingredient in Airbags Might Turn Explosive

Ammonium nitrate, commonly used as a fertilizer, is also used in airbags

WSF logo small

An airbag can save your life, but if improperly manufactured, it could mean your death. At least five people have died after airbags made by Japanese company Takata exploded during deployment in crashes, bombarding passengers with sharp metal fragments. Now more than 14 million cars using the airbags are up for recall worldwide. The recall highlights a delicate balance of electrical, mechanical, and chemical processes inside an airbag—all of which are vulnerable to contamination and failure.

First, some background on how airbags work: Before an airbag deploys, the control unit has to detect a crash through various sensors on the car. Crash sensors are rigged to detect the sudden deceleration of a crash, but not be affected by the normal stopping and starting of driving. One form of sensor is the “ball and tube” setup, where a small metal ball is held in place by a magnet. In the event of a collision, the ball detaches from the magnet, rolls down and completes an electrical circuit that triggers the inflation. Similar sensors use weights connected to a coiled-up spring that unrolls with a sudden stop. Another type of sensor can be located inside the front doors, where it monitors air pressure; a collision from the side that pushes the door inwards will change the air pressure, and trip the sensor.

WORLD SCIENCE FESTIVAL: How To Survive A Spaceship Disaster

If the sensor detects a crash, it tells the airbag’s inflator system to kick into gear. Most airbags are inflated when the inflator unit ignites a pellet of a compound called sodium azide (NAN3), kickstarting a swift chemical reaction that fills up the airbag with nitrogen gas (N2), sending it bursting out to cushion a car’s occupants. All of this happens within less than half the time it takes you to blink once.

But in the 1990s, Takata started looking for alternatives to sodium azide, due to the fact that the compound could release toxic fumes when the airbags deployed. First, the company’s engineers replaced the sodium azide with a compound called tetrazole. But tetrazole, while less toxic than sodium azide, proved more expensive. Eventually, over the objections of some employees, Takata developed a propellant using the ammonium nitrate (NH4NO3), more commonly used as a fertilizer.

WORLD SCIENCE FESTIVAL: Why Lethal Injections Fail

Ammonium nitrate “shouldn’t be used in airbags,” Missouri University of Science and Technology explosives expert Paul Worsey told the New York Times, saying the compound is really better for large-scale demolitions. “But it’s cheap, unbelievably cheap.”

Part of the danger with ammonium nitrate lies in the compound’s ability to transition through various solid states due to changes in temperature, pressure and moisture. The transition point between state IV, called beta-rhombic, and state III, called alpha-rhombic, occurs at 32.3 degrees Celsius (89.6 degrees Fahrenheit). The temperature cycles that a car experiences through days and nights, especially in hotter and more humid areas, may be enough to cause the compound to switch between these crystalline states, making it less stable.

WORLD SCIENCE FESTIVAL: Some Assembly Required

Takata senior vice president Hiroshi Shimizu told U.S. lawmakers in early December that the true cause of the airbag ruptures is still unknown, and the company has advocated for recalls to be limited to humid regions. Meanwhile, while still not characterizing its airbag propellant as defective, Takata has quietly modified the recipe for the propellant used in the replacement bags for recalled cars—though ammonium nitrate still remains a key component.

This article originally appeared on World Science Festival.

TIME Reproductive Health

The Second Most Popular Form of Birth Control Will Surprise You

102758095
Getty Images

Looks like the pill has some competition

About 62% of U.S. women from ages 15 to 44 use some form of contraception, and predictably, the pill is still the most popular. About 16% of women used it in 2011-2013, finds the latest report from the Centers for Disease Control and Prevention’s (CDC) National Center for Health Statistics.

But the second most popular contraceptive may come as a surprise to many: 15.5% of women—just a hair behind the pill—choose female sterilization. The CDC report shows that nearly one in three women ages 35 to 44 opted for female sterilization. By contrast, fewer than 1% of women between ages 15 to 24 chose it.

The rates of women choosing to undergo the simple, yet irreversible, surgical procedure might seem high, “until you start to peel back the layers and intricacies around forming a family,” says Dr. Vanessa Cullins, vice president of external medical affairs at Planned Parenthood Federation of America, who was not involved with the research. “Consider the fact that the majority of women in this country have had the number of children they want to have by mid-twenties to thirty or so—and they still have the capacity to get pregnant until they are 50 years old.” For a lot of women, that can mean 20 fertile years during which a woman may not want to become pregnant.

Cullins says women who tend to ask about sterilization don’t want to be bothered by other methods, even those that only require intervention every few years. The overall rate is slightly less than previous years, the CDC says, and Cullins says she expects the rate to continue to decline as long-acting contraceptives, especially the intrauterine device (IUD), become more popular and more affordable in the U.S.

But for now, the pill, female sterilization and condoms are more popular than the IUD. Long-acting reversible contraceptives, like the IUD and implant, remained stable from prior years, at 7.2% of women. They were most popular among women aged 25 to 34 and less popular among younger, sexually active women between ages 15 to 24. Women between ages 35 and 44 were the least likely to use them.

Because the IUD is much more convenient than the pill, with a lower failure rate, it may prove to be a bigger birth control contender in the future, some health experts say. And there are signs that with increased affordability and access, young women will opt for it. One recent study showed that when teenage girls were counseled about birth control and given their pick for free, a full 72% of them chose the IUD.

TIME France

France Wants to Sedate the Terminally Sick Until Death

President Francois Hollande delivers his speech about reform of end-of-life treatment at the Elysee Palace in Paris Dec. 12, 2014.
President Francois Hollande delivers his speech about reform of end-of-life treatment at the Elysee Palace in Paris Dec. 12, 2014. Jacky Naegelen—Reuters

French President calls for "the right to deep, continuous sedation until death" for the terminally ill

PARIS — France’s president wants to allow doctors to keep terminally ill patients sedated until death comes, amid a national debate about whether to legalize euthanasia.

Francois Hollande stopped short of recommending lethal injections, avoiding the terms euthanasia and assisted suicide, highly sensitive issues in this majority-Catholic country.

Instead, he called Friday for a law that would give people “the right to deep, continuous sedation until death” — at patients’ request, and only when their condition is life-threatening in the short term. Doctors are divided about this kind of terminal sedation.

Debate over end-of-life legislation resurfaced this year over the case of comatose Frenchman Vincent Lambert. His wife wants doctors to stop life support but his parents disagree. The case is pending at the European Court of Human Rights.

TIME Health Care

California Battles Worst Whooping Cough Epidemic in 70 years

Officials blame poor vaccine introduced in the 1990s for rise in cases

SAN DIEGO — California officials are battling the worst whooping cough epidemic to hit the state in seven decades as a recent rebound in cases raises questions about the effectiveness of the pertussis vaccine.

Doctors emphasize that the inoculation has led to fewer deaths than in the past and in instances where people do get sick, their illnesses aren’t as severe. But California officials say the limited protection of the vaccine introduced in the 1990s has led to the rise in cases. Research has shown it doesn’t last as long as the one it replaced, and a new study suggests the vaccine may not prevent the spread of the disease.

Whooping cough peaks every three to five years, and California’s last epidemic was in 2010. But despite an aggressive public health campaign in response, the current outbreak is worse.

A total of 9,935 cases were reported to the California Department of Public Health from Jan. 1 to Nov. 26 — the highest number in 70 years. The cases included one infant who died. Elementary, middle and high school outbreaks have occurred across the state.

The bacterial infection causes uncontrollable, violent coughing, which often makes it hard to breathe. People often take deep breaths which result in a “whooping” sound.

San Diego County is among the hardest hit areas with 1,819 cases reported so far this year.

“We’d have to go way back to the 1940s to find more cases,” said Dr. Eric McDonald, medical director of the epidemiology and immunization branch for public health services in San Diego County.

That’s when whooping cough was common, causing hundreds of thousands of illnesses annually and thousands of deaths. But after a vaccine was introduced in the 1940s, cases dropped to fewer than 5,000 a year.

That vaccine was replaced in the 1990s because of side effects, which included pain and swelling from the shot and fever. The newer vaccine is part of routine childhood vaccinations as well as adult booster shots.

Last year was the nation’s worst year for whooping cough in six decades— U.S. health officials received reports of more than 48,000 cases, including 18 deaths. This year the number of reported cases nationwide dropped to about 20,000.

After the 2010 epidemic, California launched a campaign about the importance of rapid diagnosis and treatment, especially in young infants. The state also started providing free vaccines for children, pregnant and postpartum women.

Dr. Gil Chavez, epidemiologist with the California Department of Public Health, said while more people, especially pregnant women, need to get vaccinated, he does not believe low inoculation rates are the primary cause of the current epidemic: Of this year’s pediatric cases that had information on the child’s vaccination history, only 10 percent of those infected in 2014 had not been vaccinated against pertussis.

Chavez says the new vaccine’s limitations and better tests have led to the increase in cases.

Cases are likely to continue going up as doctors do a better job at detecting the illness, officials say.

More than two years ago, Kathryn Riffenburg, who lives outside Boston, said doctors told her that her newborn son, Brady, likely had a cold. A week and a half later, she took him to the emergency room as he struggled to breathe.

By the time, he was diagnosed with pertussis it was too late to save the 2-month-old boy.

“It made us angry, because we felt more should have been done,” said Riffenburg, who know advocates for pregnant women and anyone else in contact with infants to get vaccinated.

TIME ebola

U.N.: Ebola Outbreak Will Take Several More Months to Contain

Liberia Ebola Missed Goals
Health workers wearing Ebola protective gear spray the shrouded body of a suspected Ebola victim with disinfectant at an Ebola treatment center at Tubmanburg, on the outskirts of Monrovia, Liberia, on Nov. 28, 2014 Abbas Dulleh—AP

The U.N. goal of containing 100% of Ebola cases by Jan. 1 will not be met

The U.N.’s special envoy on Ebola said Thursday that it would be several months before the outbreak in West Africa is under control.

Dr. David Nabarro said international governments as well as local communities had taken a “massive shift” in responding to the crisis over the past four month, the Associated Press reports.

However, he noted that more needed to be done to contain the spread of the disease in western Sierra Leone and northern Mali.

“It’s going to take, I’m afraid, several more months before we can truly declare that the outbreak is coming under control,” Nabarro said.

The World Health Organization aimed to have 100% of cases isolated by Jan. 1, but acknowledges that previous targets have not been met.

[AP]

TIME europe

The E.U. Plans to Spike Key Clean-Air and Recycling Laws

Prime Minister David Cameron Tries To Take A Harder Line with Europe
E.U. flags are pictured outside the European Commission building in Brussels on Oct. 24, 2014 Carl Court—Getty Images

The proposed laws are aimed at preventing tens of thousands of premature deaths and set a 70% recycling target by 2030

The E.U. is planning to scrap environmental laws aimed at averting tens of thousands of possible deaths, according to classified documents published on Thursday.

The leaked files propose the withdrawal of a plan for a clean-air law as well as a directive setting a target of 70% waste recycling by 2030, the Guardian reported.

The plan is reportedly being withdrawn because the commission in charge of it sees “no foreseeable agreement” with states that have a poor track record on recycling, and would not be able to meet the target without additional financial help.

Read more at the Guardian

TIME infectious diseases

Avian Flu Outbreak in British Columbia Spreads to Seven Farms

The virus has affected 155,000 birds in the past week

A sudden spike in avian influenza cases in British Columbia in the past week has now spread to seven farms and affected thousands of birds, according to the Canadian Food Inspection Agency.

Some 155,000 birds have either died or will be euthanized, the Associated Press reports.

The outbreak originated in the Fraser Valley near Vancouver last week, where turkeys and chickens from two farms tested positive for the H5N2 strain of the virus.

Although the bug does not pose a major threat to humans as long as the meat from these birds is cooked properly, its sudden resurgence a huge blow to the region’s poultry industry.

[AP]

TIME Infectious Disease

Superbugs Could Kill 10 Million By 2050, Report Warns

Could be deadlier than cancer

Rising rates of drug-resistant infections could lead to the death of some 10 million people and cost some $100 trillion in 2050.

That’s the startling conclusion of a review commissioned by British Prime Minister David Cameron which has warned that if antimicrobial resistance is not curbed, it could undermine modern medicine and cut up to 3.5% from the global economy.

The threat could also disproportionately affect the developing world, according to the report authored by economist Jim O’Neill, leading to more than 4 million deaths in Africa and 4.7 million deaths in Asia. By comparison, cancer killed 8.2 million people worldwide in 2014.

The report, which will be followed up by a full package of public health recommendations by 2016, called for “coherent international action that spans drug regulation and antimicrobial drugs use across humans, animals and the environment.”

Specifically, the report said that antibacterial research, the use of alternatives like vaccines and international measures to reduce the spread of bacteria could help reduce the threat from drug-resistant infections.

“It would be unforgiveable if the great progress made in combatting infectious diseases could be threatened by the lack of new drugs that are within reach, or for lack of common sense investment in infrastructure that keeps us safe from avoidable infections,” says the report.

Read the entire report here.

TIME Infectious Disease

Whooping Cough Outbreak Strikes Undervaccinated Michigan County

Grand Traverse County has the state’s highest rates of parents choosing not have their children vaccinated

A major outbreak of whooping cough has struck a Michigan area where many people opted out of vaccinations against the disease.

At a single school in Grand Traverse County, which has the state’s highest rates of parents choosing not have their children vaccinated, there have been 151 confirmed and probable cases of whooping cough, reports local news outlet MLive.com.

“Nobody likes to be the person who says, ‘I told you so,’ but what’s unfolding now is exactly the scenario feared by those worried about the region’s low immunization numbers,” Bradley Goodwin, the president of the Grand Traverse County Medical Society, said.

Cases of whooping cough have been reported at more than 14 school buildings in the area, which has also reported several cases of the highly contagious measles.

Read more at MLive.com

TIME person of the year

Watch U.S. Ebola Survivors Describe Fighting the Deadly Virus

"I saw his eyes and they had been red from crying, and I knew immediately"

Dr. Kent Brantly vividly remembers the day he was told he had Ebola. A missionary doctor with Samaritan’s Purse in Liberia, Brantly had been treating Ebola patients and was familiar with the deadliness of the disease.

And yet, he didn’t panic when a colleague broke the news.

“It was really a very surreal moment. It was a very solemn moment,” Brantly says. “I felt a very strange but overwhelming sense of peace.”

For Dallas nurse Nina Pham, who had cared for Ebola patient Thomas Eric Duncan at Texas Health Presbyterian in Dallas, learning that she tested positive for Ebola was devastating news.

“Because Mr. Duncan had died three days prior, flashbacks started coming to my head of how his disease progressed and eventually led to his death,” Pham says.

In the video above, Brantly and Pham, along with nurse Amber Vinson, Dr. Rick Sacra and medical aide Nancy Writebol — all of whom have survived Ebola — recount their experiences.

TIME named Ebola Fighters as the 2014 Person of the Year. Read the full story here.

Your browser, Internet Explorer 8 or below, is out of date. It has known security flaws and may not display all features of this and other websites.

Learn how to update your browser