GEORGE NEWS - Christo Fabricius, Professor Emeritus at Nelson Mandela University, shares the latest on the impact of light pollution:
The Garden Route has always been a place where nature’s beauty can be enjoyed and protected, including clear nights filled with stars. But recently, more and more artificial light at night - what we call 'light pollution' - is taking away this simple pleasure while also affecting urban nature.
More than that, like air and water pollution, it’s also starting to affect our health.
Scientific research shows that too much light at night can harm our sleep, disrupt our body’s natural rhythms, and increase the risk of conditions like Alzheimer’s disease. It’s time for our community to think about how we use outdoor lighting.
A growing body of research, including studies published in The Journal of the American Medical Association and Frontiers in Neuroscience, reveals that artificial light at night can prevent our bodies from making enough melatonin, a hormone that helps us sleep and keeps our brains healthy.
When we don’t sleep well, the brain can’t clean out harmful proteins like beta-amyloid, which is linked to Alzheimer’s disease. The effects of too much artificial light at night go beyond just sleep loss - they may have a lasting impact on our memory and thinking as we get older.
In the most recent study published in Frontiers in Neuroscience, researchers analysed satellite data to measure night-time light exposure across US states and counties. They compared this information with Medicare data on Alzheimer’s disease prevalence and found a strong, statistically significant relationship: areas with higher levels of night-time lighting had notably higher rates of Alzheimer’s. This relationship held true even when controlling for other health risk factors. Surprisingly, people under the age of 65 seemed more sensitive to the effects of night-time light exposure, suggesting that younger individuals may face greater long-term risks than previously thought.
The good news is that reducing light pollution is possible and could greatly benefit our health and quality of life.
Simple changes like using shielded lights, choosing softer, warmer bulbs, using motion-triggered spotlights and turning off unnecessary lights at night can make a difference. These changes will not only help protect our health but also keep our night sky beautiful for everyone to enjoy.
Our local leaders and neighbours should seriously consider supporting responsible lighting practices and start thinking about policies to limit unnecessary night-time lighting.
Reducing light pollution isn’t just about the environment; it’s about making the Garden Route a healthier and more beautiful place for all of us.
References
1. Voigt, R. M., Ouyang, B., & Keshavarzian, A. (2024). Outdoor nighttime light exposure (light pollution) is associated with Alzheimer’s disease. Frontiers in Neuroscience, 18, 1378498. doi:10.3389/fnins.2024.1378498. This study used satellite data to correlate nighttime light levels with AD prevalence, revealing that higher light exposure areas had significantly higher rates of AD, especially among individuals under 65 .
2. Chen, Y., Tan, J., Liu, Y., et al. (2022). Long-term exposure to outdoor light at night and mild cognitive impairment: a nationwide study in Chinese veterans. Science of the Total Environment, 847, 157441. doi:10.1016/j.scitotenv.2022.157441. This research highlighted the relationship between light pollution, sleep disruption, and cognitive impairment, focusing on a population sensitive to environmental changes.
3. Colwell, C. S. (2021). Defining circadian disruption in neurodegenerative disorders. Journal of Clinical Investigation, 131(3), e148288. doi:10.1172/JCI148288. This paper examined how disruptions in circadian rhythms due to light exposure can worsen symptoms in neurodegenerative diseases, including Alzheimer’s.
4. Bubu, O. M., Brannick, M., Mortimer, J., et al. (2017). Sleep, cognitive impairment, and Alzheimer’s disease: a systematic review and meta-analysis. Sleep, 40(1). doi:10.1093/sleep/zsw032. This study reviewed sleep’s role in preventing Alzheimer’s disease by allowing for the clearance of neurotoxic proteins, like beta-amyloid, that build up with sleep disruption due to light exposure.
5. Bedrosian, T. A., & Nelson, R. J. (2013). Influence of the modern light environment on mood. Molecular Psychiatry, 18(7), 751-757. doi:10.1038/mp.2013.70. This study investigated how artificial light affects melatonin production, impacting mood and potentially accelerating neurodegenerative processes.
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