Do Wind Turbines Affect Your Health?

Wind power has emerged as one of the fastest growing renewable energy sources in the world. Wind turbines capture the wind’s kinetic energy and convert it into electricity. According to the American Clean Power Association, wind power capacity grew at a rate of 12% annually between 2012 and 2022. As of 2022, global wind energy capacity reached over 900 GW, providing around 6% of global electricity demand.

The development of larger, more efficient wind turbines has helped drive rapid growth in wind power generation. Modern wind turbines can reach heights over 300 feet tall with blade lengths over 200 feet long. Continued advancements in wind turbine technology are expected to further expand wind energy’s role in powering the global economy.

Potential Health Concerns

Some people have raised concerns that wind turbines may negatively impact human health. The main concerns that have been raised include noise, infrasound, visual impacts, and shadow flicker.

Wind turbines produce aerodynamic noise from the rotation of turbine blades cutting through the air. This can be perceived as a nuisance to people living near wind farms. However, numerous studies have found that the levels of noise produced by modern wind turbines are generally not sufficient to cause health issues for most people (1, 2).

Infrasound refers to very low frequency sounds that are below the normal hearing threshold of humans. Some people believe that infrasound from wind turbines can lead to symptoms like nausea, headaches, and sleep disturbances. However, infrasound levels from wind turbines at residential distances are typically well below established perception thresholds (1, 2).

The visual impact and shadow flicker created by rotating turbine blades is another concern sometimes raised regarding wind farms. However, researchers have found no evidence directly linking them to health issues (1). Careful siting, community engagement, and mitigation strategies can help reduce visual annoyances.

Overall, the bulk of scientific evidence to date does not support a direct causal link between wind turbines and negative health impacts for most people (1, 2, 3). However, some individuals may be more sensitive to the audible and inaudible noise generated by wind turbines. More research is needed on determining safe setback distances and developing mitigation strategies.

Noise

Audible noise from wind turbines is generally not high enough to negatively impact health according to most studies. The noise emitted from wind turbines is comparable to ambient noise in the range of 35-45 decibels at a distance of 300 meters according to the U.S. Department of Energy (https://windexchange.energy.gov/projects/sound). This is about the level of noise produced by a refrigerator humming. GE Renewable Energy states that background noise ranges from 40-45 decibels in most places, meaning the audible noise from turbines would often blend into ambient noise (https://www.ge.com/news/reports/how-loud-is-a-wind-turbine). While audible noise from turbines can sometimes be detected by the human ear, it is generally not at levels considered dangerous to health.

Infrasound

Infrasound is defined as sound at frequencies below 20 Hz, which is below the normal range of human hearing (20 Hz to 20,000 Hz). Wind turbines do generate low levels of infrasound, but multiple studies have found the infrasound near wind farms is well below the perception threshold for humans and does not present a health risk (Frochio, 2022[1]).

For example, one 2021 study measured infrasound around wind turbines in Germany and found levels ranging from 65 to 85 dBG, while the median hearing threshold for infrasound is around 100 dBG. The study concluded: “The results show that the infrasonic emissions from wind turbines cannot be the cause of adverse health effects” (Betke et al, 2021[2]).

Overall, while wind turbines produce low levels of infrasound, studies consistently show the levels are orders of magnitude below what could potentially cause health effects in humans.

[1] Reference to insert
[2] Reference to insert

Visual Impact

The visual impact of wind turbines refers to how they affect the aesthetics and scenery of the surrounding landscape. This includes considerations such as their overall appearance, size, layout, how noticeable they are, and shadow flicker effects.

Modern wind turbines can have towers up to 300 feet tall and blades spanning over 400 feet in diameter. Their large size and tall height can make them visible from long distances. Studies like the Wind Turbine Visibility and Visual Impact Threshold Distances report have analyzed visibility thresholds based on turbine size, terrain, and weather conditions.

The placement and density of multiple turbines in a project area also affects the visual landscape. Blocks of turbines clustered together can create more visual contrast compared to scattered individual turbines. Visual impact analyses consider the layout and attempt to mitigate large contrasts through careful siting.

Shadow flicker from turbine blades can be noticeable during certain times of day when the sun is low on the horizon. It appears as moving shadows on the landscape. Proper siting and analysis of flicker zones based on sun position can help reduce this effect.

Studies on Wind Turbines and Health

Several studies have examined the potential health effects of wind turbines. A 2015 meta-analysis of six studies involving 2,364 participants found that exposure to wind turbine noise was associated with increased odds of annoyance (OR: 4.08; 95% CI: 2.37 to 7.04), but no evidence of an effect on sleep or health-related quality of life was found (https://pubmed.ncbi.nlm.nih.gov/25982992/).

Another review published in 2021 examined 45 studies on wind turbines and health. While annoyance and sleep disturbance were frequently reported, the meta-analysis of quantitative studies was inconclusive regarding a causal link between wind turbine exposure and health effects. The authors noted that sound annoyance seems more strongly related to individual factors like noise sensitivity rather than sound levels alone (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8430592/).

Overall, these reviews indicate that annoyance is the main issue associated with wind turbines, especially among noise-sensitive individuals. However, high quality evidence demonstrating impacts on physical health remains limited.

WHO Guidelines

The World Health Organization (WHO) has published noise guidelines that recommend noise levels for the protection of human health. In its Environmental Noise Guidelines, the WHO states that night noise exposure levels from wind turbines should be below 45 dB Lden to limit sleep disturbance.

The WHO also notes that noise levels below this may still cause sleep disturbance, especially in vulnerable groups like children, the chronically ill, and the elderly. They recommend mitigation measures like setback distances and noise optimizing techniques to reduce noise exposure from wind turbines.

According to the WHO guidelines, the evidence available suggests no substantial health effects from wind turbines at distances greater than 500-600 meters. However, they note that subjective effects like annoyance remain an issue and should be addressed through proper siting and community engagement.

Potential Explanations

One potential explanation for health complaints associated with wind turbines is the nocebo effect. The nocebo effect refers to negative health effects that are not caused by any external stimuli, but rather by people’s negative expectations or previous associations. Some research has found evidence that just being informed about potential health impacts from wind turbines can actually cause people to develop symptoms, even when no turbines are present. This was demonstrated in a New Zealand-based study, where healthy volunteers who watched clips focused on potential infrasound impacts experienced an increase in symptoms vs. a control group (Crichton et al., 2015).

The nocebo effect may explain why some people living near wind turbines report health issues while others do not. If someone expects to experience negative effects or has an ideological opposition to wind power, they may be more likely to notice normal symptoms and attribute them to the turbines. This results in an increase in reported complaints that is not matched by objective health measures.

In addition to nocebo effects, anxiety and stress related to wind turbines could also lead to or exacerbate symptoms. Some researchers have suggested that anti-wind advocacy and negative media portrayals may increase worries and prime people to interpret normal phenomena as dangerous. More research is still needed, but initial studies point towards psychological factors as more plausible explanations than direct health impacts from turbine exposure.

Mitigation

There are several ways to mitigate the potential negative impacts of wind turbines on health and quality of life. According to How to Reduce Noise and Vibrations from Wind Farms, using vibration damping techniques can significantly reduce noise from wind turbines. Materials like rubber and neoprene can be installed between turbine components to absorb vibrations and noise.

Many jurisdictions have regulations on wind turbine setbacks and noise limits. Setbacks require turbines to be located a certain distance away from homes and populated areas. This helps reduce noise impacts. Noise limits regulate the maximum allowable noise turbines can produce at nearby homes. Shadow flicker sensors can also be installed to shut turbines off when they would otherwise cast disruptive shadows on homes.

Conclusions

In summary, the available evidence suggests that wind turbines are unlikely to pose a significant risk to human health when sited properly. While wind turbines can produce low-frequency noise and infrasound, sound pressure levels are typically below thresholds considered harmful. Numerous studies have found no direct link between living near wind turbines and negative health impacts. Minor effects like annoyance and sleep disruption have been reported in some cases, but these can often be mitigated through proper siting and noise-reduction technologies. Though more research is still needed, findings to date indicate that wind power can be harnessed as a clean energy source without compromising public health through noise or other mechanisms.