Living inshore increases your life years, while inland waters can cut you short

Living inshore increases your life years, while inland waters can cut you short

Where do you live, by the sea or by the inland lake, how do you live your lifespan? Discover why coastal living adds years and why blue rooms don't always mean better health.

In a first-of-its-kind study published in the journalEnvironmental researchResearchers examined the effects of coastal and inland proximity on life expectancy in both urban and rural communities in the United States (US).

background

Did you know that where you live, especially how close you are to water, could affect how long you live? Life expectancy, an important indicator of overall well-being, is influenced by factors such as income, healthcare and environmental conditions. While the benefits of green spaces are well known, “blue spaces” such as oceans, lakes and rivers are gaining attention for their effects on both mental and physical health. Coastal areas often provide cooler temperatures, better air quality and recreational benefits, while inland waters have mixed impacts. Direct research into how these spaces affect life expectancy has been non-existent worldwide - a gap that this landmark study addresses.

About the study

Researchers examined 66,263 census tracts in the contiguous United States and used life expectancy data from 2010 to 2015 from the Centers for Disease Control and the U.S. National Life Expectancy Survey. Blue space pollution was measured in two ways: proximity to coastal waters (within 0, 20, or 50 kilometers) and the presence of large inland waterways (at least 10 or 20 square kilometers). Environmental data, including air pollution (PM₂.₅ and wildfire smoke), terrain features, temperature extremes, and drought susceptibility (measured by the standardized precipitation index), were collected from national sources. Socioeconomic data, including income and population demographics, were obtained from the American Community Survey.

Analytical approaches included multiple linear regressions, multilevel models (to account for state-level variations), and spatial regression (addresses geographic clustering). A mutual information model was applied to identify key factors that differentiate the water and inland water professional tracts. Sensitivity analyzes tested alternative definitions of blue space exposure. Special statistical software was used in all analyses, with a particular focus on urban-rural differences.

Study results

Life expectancy in the United States averaged 78.3 years in census tracts. Multi-level regression revealed that proximity to coastal waters (within 50 km) significantly increased life expectancy (β = 0.32), while proximity to inland waters (≥ 20 km²) overall decreased it (β = -0.14). Critically, inland waters showed different effects: urban exposure decreased longevity (β = -0.39), but rural exposure increased it (β = 0.22).

Mutual information analysis identified the most influential differences between coastal and inland tracts: coastal tracts had far fewer hot days (2.2 vs. 21.0 days per year), lower maximum temperatures (34.3 °C vs. 37.7 °C), higher barren land cover (0.65% vs. 0.13%), and better air quality (µg/m³).

Coastal benefits included milder temperatures, fewer smoking days (30.6 vs. 40.3 annually), flattering terrain (Road Tri Count: 633.6 vs. 1,759.7), reduced drought vulnerability, and significantly higher incomes ($91,075 vs. $67,775). Urban-rural differences emerged in other factors: population density increased urban longevity (β = 0.49), but decreased rural longevity (β = -9.73), while the increase benefited only rural residents (β = 0.62).

Conclusions

This groundbreaking research confirms that the influence of blue space on longevity is not universal. Living near coastal waters extends life expectancy through milder climates, cleaner air, recreational access, transportation advantages, and higher incomes. In the areas Water bodies have dependent impacts: they are harmful in urban areas due to pollution and flood risks, but beneficial in rural settings. These findings call for context-sensitive integration of blue spaces into public health planning. The authors acknowledge limitations including the cross-sectional design of the study and the lack of data on water quality and recreational use. Urban planners and policymakers can use these insights to design health communities and address spatial health disparities across the country.

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