From Sunshine to Screen Glow: The Indoor Epidemic of the Past Century

From Sunshine to Screen Glow: The Indoor Epidemic of the Past Century

The transition from open fields to urban sprawls, from sunny days in the park to fluorescent-lit offices, is more than just a societal shift. It's a health concern of epidemic proportions. Over the past 100 years, our relationship with sunshine has transformed dramatically, with profound implications for our well-being. Let's dive into this sunny predicament.

The Indoor Migration

The beginning of the 20th century saw people spending a majority of their time outdoors, be it for work, recreation, or daily chores. Fast-forward to today, and a study suggests that the average American spends a staggering 93% of their time indoors1. That's a mere 7% of our entire day spent under the open sky. The gradual switch to indoor living is astonishing:

  • 1920s: 75% outdoors
  • 1950s: 60% outdoors
  • 1980s: 50% outdoors
  • 2000s: 20% outdoors
  • 2020s: 7% outdoors

1 Klepeis, N. E., et al. (2001). The National Human Activity Pattern Survey (NHAPS): a resource for assessing exposure to environmental pollutants. Journal of Exposure Science & Environmental Epidemiology, 11(3), 231-252. Direct link

A Dim Light on Mental Health

Our shift indoors hasn't just robbed us of sunlight, but possibly of our happiness too. Sunlight exposure is critical for the synthesis of serotonin, a neurotransmitter that uplifts mood and wards off depression2. Consequently, lesser sunlight can mean lesser serotonin, setting the stage for mood disorders.

2 Lambert, G. W., et al. (2002). Effect of sunlight and season on serotonin turnover in the brain. The Lancet, 360(9348), 1840-1842. Direct link

The ‘Sunshine Vitamin’ Deficiency

Vitamin D, aptly named the 'sunshine vitamin', requires sun exposure for synthesis in our skin. With our dwindling time outdoors, it's no surprise that Vitamin D deficiencies are rampant. In the U.S., over 40% of the population is deficient3, a staggering figure that brings with it a host of health concerns, from bone disorders to immune system vulnerabilities.

3 Forrest, K. Y., & Stuhldreher, W. L. (2011). Prevalence and correlates of vitamin D deficiency in US adults. Nutrition research, 31(1), 48-54. Direct link

A Blow to Reproductive Health

The sun, in all its golden glory, has a significant role in modulating reproductive hormones. Reduced sunlight exposure, thus, has repercussions on fertility and reproductive health. Recent studies indicate that men with low Vitamin D levels have lower testosterone, which can impact fertility4. With indoor confinement, we may inadvertently be compromising our reproductive futures.

4 Lerchbaum, E., & Obermayer‐Pietsch, B. (2012). Mechanisms in endocrinology: Vitamin D and fertility: a systematic review. European Journal of Endocrinology, 166(5), 765-778. Direct link

The Broader Implications

This indoor epidemic isn't just a personal health crisis. It’s a societal one. From reduced productivity due to mood disorders to the medical costs associated with Vitamin D deficiencies and fertility treatments, the implications are far-reaching.


The modern era, with its digital glow and urban allure, has inadvertently caged us indoors, moving us further from our inherent connection with the sun. We must acknowledge this sun-deficit situation and actively reintegrate sunshine into our daily lives. Whether it's lunch breaks in the park, morning yoga in the garden, or simply reading by the window, every ray counts.

Remember, in a world dominated by screens and ceilings, let's not forget the natural screen above us, painting its hues from dawn to dusk. The solution might just be a step outside.

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