Sources: Environmental and Health Issues

While leaded gasoline was fully phased out in 1996 with the passage of the Clean Air Act, it still fuels a fleet of 170,000 piston-engine airplanes and helicopters. Leaded aviation fuel, or avgas, now makes up “the largest remaining aggregate source of lead emissions to air in the U.S.,” according to the Environmental Protection Agency.
The presence of this fuel means the areas near these airports are often inundated with tiny lead particles, according to a 2020 report from the EPA. Lead has been proven to have a detrimental impacton children’s brains and nervous systems.

After 15 years of research, the EPA said it wouldissue a ruling, known as an “endangerment finding,” in 2018 that would unlock a legal mandate to start driving down leaded aviation fuel. But it has yet to do so. “EPA will follow the science and law in developing any future decisions regarding lead emissions from piston-engine aircraft,” said Enesta Jones, an EPA spokesperson.For now, leaded aviation gas appears to be caught in a bureaucratic limbo: stuck between not meeting the environmental demands of the EPA and the commercial realities of the aviation community. It is the primary viable option for this type of aircraft, as the general aviation community argues it remains critical given the needs of the current fleet.

When the EPA first tackled removing lead emissions from engines, it focused on the biggest polluters: cars. At the time, the automotive industry made up the vast majority of airborne lead, with piston-engine airplanes responsible for only about 5 percent of emissions. Technological advances in auto engines, such as cooling liquid, also made way for a new market for unleaded fuel. But there were no alternatives for piston engines, so they were largely left out of federal regulation. Piston-engine aircraft are now the largest single remaining source of airborne lead, according to a 2016 EPA study. Approximately one-quarter of the piston-engine fleet are estimated to “consume more than half of all avgas,” according to a January reportby the National Academy of Sciences.

David Owen reports on noise pollution, an intangible phenomenon with serious costs to human health and wildlife.

Aircraft noise is the most annoying by far. Münzel had read a 2009 World Health Organization (WHO) report linking noise to heart problems, but evidence at the time was thin. Driven in part by concern for his own health, in 2011 he shifted the focus of his research to learn more. Exposure to loud noise has long been linked with hearing loss. But the ruckus of planes and cars takes a toll beyond the ears. Traffic noise has been flagged as a major physiological stressor, second to air pollution and on roughly equal footing with exposure to second-hand smoke and radon. In the last decade, a growing body of research has linked noise from aircraft and road traffic to a heightened risk for a number of cardiovascular ailments. And scientists are also beginning to pinpoint the mechanisms at play.

The science behind helicopter noise – and how the industry is working to reduce it: The topic of noise is never far away from many helicopter operators. We look at where it comes from, why helicopter noise seems to generate disproportionate level of complaint, and whay ccan be done to help reduce it..

Ambient noise is the new secondhand smoke (Fetterman, 2018). Like unwanted tobacco smoke, noise doesn’t just bother people but also adversely affects human health and function..

Our findings indicate that a chronic environmental stressor-aircraft noise-could impair cognitive development in children, specifically reading comprehension. Schools exposed to high levels of aircraft noise are not healthy educational environments.

Unwanted and disturbing sound increases the risk for a variety of negative health outcomes such as heart disease, diabetes, hypertension, hearing loss, and sleep disturbance. While current federal and local policy is fragmented, the infrastructure for greater collaboration is available and ready to be utilized to improve public health outcomes. The American Public Health Association should archive the policy statement on noise from 1975 and advocate for the implementation of a federal noise control plan through the United States National Prevention Strategy. Federal leadership in noise monitoring, research, and education will help local governments abate the negative health outcomes associated with environmental noise pollution.

“Noise doesn’t just affect hearing, noise activists say. A study by the University of Michigan showed an association with cardiovascular disease and heart attacks, according to Neitzel, who conducted the study. “The consensus is that if we can keep noise below 70 decibels on average, that would eliminate hearing loss,” Neitzel said. “’But the problem is that if noise is more than 50 decibels, there’s an increased risk of heart attack and hypertension,” he said. “Noise at 70 decibels is not safe.’”

“Scientists have known for decades that noise—even at the seemingly innocuous volume of car traffic—is bad for us. “Calling noise a nuisance is like calling smog an inconvenience,” former U.S. Surgeon General William Stewart said in 1978. In the years since, numerous studies have only underscored his assertion that noise “must be considered a hazard to the health of people everywhere.” Say you’re trying to fall asleep. You may think you’ve tuned out the grumble of trucks downshifting outside, but your body has not: Your adrenal glands are pumping stress hormones, your blood pressure and heart rate are rising, your digestion is slowing down. Your brain continues to process sounds while you snooze, and your blood pressure spikes in response to clatter as low as 33 decibels—slightly louder than a purring cat.

Experts say your body does not adapt to noise. Large-scale studies show that if the din keeps up—over days, months, years—noise exposure increases your risk of high blood pressure, coronary heart disease, and heart attacks, as well as strokes, diabetes, dementia, and depression. Children suffer not only physically—18 months after a new airport opened in Munich, the blood pressure and stress-hormone levels of neighboring children soared—but also behaviorally and cognitively. A landmark study published in 1975 found that the reading scores of sixth graders whose classroom faced a clattering subway track lagged nearly a year behind those of students in quieter classrooms—a difference that disappeared once soundproofing materials were installed. Noise might also make us mean: A 1969 study suggested that test subjects exposed to noise, even the gentle fuzz of white noise, become more aggressive and more eager to zap fellow subjects with electric shocks.”

In 1976, EPA administrator Russell Train emphasized concerns over air-craft noise: “‘It is time for all to come together, and to come to grips with the problem of aviation noise, and to build, at long last, an air transportation system that is safe, healthy, and quieter.’” Unfortunately, this energy toward noise regulation was short-lived. In 1981, Reagan closed the Environmental Protection Agency’s Office of Noise and Abatement, originally established in 1972. From the 1980s through today, the EPA has ignored the 1972 Noise Control Act, leaving U.S. citizens with “no federal agency to advocate lessening the noise in their communities.” Legislators across the nation have tried without success to restore federal noise regulation.

Health hazards associated with noise overexposure include risk of cardiovascular diseases among older residents, sleep disturbance, hearing loss, and decreased performance. In fact, one alarming 1975 study found that “sixth grade children exposed to passing train noise were nearly a year behind in reading compared to children on a quiet side of the school building.” Sound-deadening acoustic tiles were installed in classroom ceilings, and rubber pads were installed on train tracks. With these soundproofing changes, the learning gap disappeared. It is time to leverage research on noise hazards and for the government to once again regulate noise pollution (summary provided by Grace Brennan).

There are many human health and well-being concerns from aviation noise exposure.

  1. Annoyance: Noise interference causes resentment, discomfort, and displeasure. Annoyance varies with sound level and pitch as well as with social, psychological, or economic factors. 
  2. Cognitive impairment: Aircraft noise exposure has a negative effect on reading comprehension, memory, and sustained attention. One study found that children in noisy areas are more likely to give up on difficult tasks.
  3. Sleep disturbance: awakenings, arousals in heart rate, and body movements are linked to chronic noise exposure. These disturbances may result in next-day fatigue. 
  4. Cardiovascular disease: coronary heart disease, heart attack, and stroke are associated with exposure to high levels of aircraft noise. 

This table shows the number of Quality Adjusted Life Years (QALYs) the average person loses from regular noise exposure. A QALY is a year of life lived in perfect health.  

Figures in each dB column are the number of QALYs lost per person because of the listed health effect. For instance, a person loses 0.1 to 0.2 QALYs from an increased likelihood of developing cardiovascular disease from noise exposure (summary provided by Grace Brennan).

This extensive study found “chronic exposure to aircraft noise was significantly related to poorer reading and mathematics performance.” Findings were drawn from a sample of about 11,000 children, approximately 11 years old, from 123 schools around Heathrow Airport in London. This study was the first of its kind to consider the additional impact of social class and school characteristics on student performance. Poorer reading and mathematics performance on standardized tests was significantly related to chronic aircraft noise at school. After adjusting for school social class, the association between high noise exposure and poor performance is reduced. This suggests that noise exposure is either a marker or a mediator of how social class impacts student performance. Ultimately, “both noise exposure and social class are interrelated” and both put students at risk (summary provided by Grace Brennan).

“Acoustical litter” has inspired researchers and noise activists to understand noise patterns in loud environments. The Medusa sensor from Paris non-profit Bruitparif and audio sensors from N.Y.U’s Sounds of New York City (SONYC) project can detect sources of noise pollution. This data provides evidence of noise violation to regulatory bodies. These devices are critical considering the myriad health and environmental threats of noise pollution. People who suffer from overexposure to loud sounds can develop an incurable condition called hyperacusis. They wince at the mere crumpling of a chip bag, and struggle to live or work in our noisy world. Excessive noise can also cause heart disease, high blood pressure, low birth weight, as well as physical, cognitive, and emotional issues from being too distracted or losing sleep. Human-made sounds harm animals too. Road sounds disrupt bird migration patterns, and ocean shipping noises threaten marine creatures’ feeding, mating, and communication habits (summary provided by Grace Brennan).

Calculating helicopter emissions demonstrates their concerning climate impact. For instance, taking a helicopter from the airport to the Chaa Creek eco-resort in Belize uses 3x more fuel than taking a van. Assuming at least one helicopter round-trip every day from the airport to Chaa Creek, the helicopter agency Astrum emits over 140mT GHG per year. This is 96 mT more than vans would emit. Additionally, noise pollution from helicopters impacts birds, locals, and tourists (summary provide by Grace Brennan).