In short

• Finland’s Kruunuvuori Bridge debuted with targeted, shielded fixtures that illuminate without aiming upward or toward water.
• San Francisco’s Bay Bridge lightshow, officially “Bay Lights 360”, had half of 50,000 LEDs installed by March, and Mark Baker of the Soft Lights Foundation sued over a lack of mandatory environmental review.
• Light reduced foraging activity of Denmark’s Daubenton’s bats by 43% at the source, and Reunion Island bats showed 62% to 73% more activity under partial lighting.
• Illinois passed SB3037, which creates voluntary commercial lighting standards through the Illinois Stretch Energy Code and caps color temperatures at 3000K for communities that adopt them.
• Headlight glare complaints are not new: British complaints in the 1930s sparked a cottage industry of shielding and reflectors.

This month, we had a spirited Light Pollution News as I welcomed back two past guests, Ken Walczak, formerly of the Adler Planetarium, and Mark Baker of the Soft Lights Foundation. I also welcomed charismatic author and naturalist Charles Hood to the show. This is his first appearance. You can learn more by heading over to LightPollutionNews.com and checking out June 2026: Let Bats Be Themselves! and June 2026: Avoiding Light Fetish.

Finland’s Kruunuvuori Bridge Debuts With Shielded Lighting That Avoids the Sky and the Water

In the news, Finland’s Kruunuvuori Bridge debuted. It’s a rail bridge with pedestrian pathways featuring targeted, shielded fixtures that illuminate without aiming upward or toward water.

San Francisco’s Bay Lights 360 Returns to the Bay Bridge as the Soft Lights Foundation Sues

Meanwhile, over in San Francisco, the Bay Bridge showed off its new lightshow. Illuminate’s Ben Davis raised $11 million to bring decorative lighting back after original lights degraded in 2023. Artist Leo Villareal redesigned the installation with Musco Lighting. By March, half of the 50,000 LEDs were installed, doubling the original design. Mark Baker of the Soft Lights Foundation sued, citing failure to provide mandatory environmental review. The project’s official name, “Bay Lights 360,” suggested expansion of lighting rather than restraint, with plans to extend lighting to the other side of the support cables. Interestingly, Musco Lighting’s sports lighting is endorsed by DarkSky International. Musco Lighting did not respond when asked what measures, if any, were taken to minimize light pollution impacts on the Bay Bridge.

Studies Show Light at Night Reshapes the Behavior of Bats, Spiders and Crayfish

In ecology, research found that light reduced foraging activity of Denmark’s Daubenton’s bats by 43% at the source. In a separate study, Reunion Island bats showed 62-73% increased levels of activity under partial lighting. Research on spider and crayfish food webs found light expanded spider dietary niche width by 14%. Crayfish shifted focus toward midges and amphipods under light. These studies indicate how light at night exaggerates ingrained predation behaviors.

Big Bend Faces Renewed Border Wall Threats as It Receives the Largest Wall Contract

Big Bend faced renewed border wall threats. The Trump administration allocated the largest border wall contract to the Big Bend section despite its rugged terrain and existing surveillance infrastructure.

Ontario Rolls Back Green Building Standards, Putting Dimming and Shielding at Risk

Ontario dismantled green building standards through three bills. Things like dimming and shielding may be effectively eliminated.

Illinois Passes SB3037, Creating Voluntary Outdoor Lighting Standards

On the positive side, Illinois passed SB3037 establishing voluntary lighting standards for commercial buildings via the Illinois Stretch Energy Code. If adopted by a community, standards would limit outdoor lighting to 25% of IES standards and cap color temperatures at 3000K.

Wild Mice Under 10-15 Lux Lose 24-Hour Immune Rhythms and Face 2.35 Times the Death Risk

Artificial light disrupted immune timing in wild rodents. Mice facing 10-15 lux lighting lost 24-hour immune rhythms and faced 2.35x greater death risk.

Bedroom Light Above 50 Lux Worsens Hepatic Encephalopathy in Cancer Patients

Bedroom light pollution above 50 lux worsened hepatic encephalopathy in cancer patients.

Continuous Light During Pregnancy Causes Lasting Gut Bacteria Damage in Offspring

Continuous artificial light during pregnancy caused lasting gut bacteria damage in offspring.

Headlight Glare Complaints Date to the 1930s, When France and the UK Acted

Are you sick of headlight glare? Well, you’re not alone! So were your grandparents! Headlight glare isn’t new! In the 1930s, British complaints about bright headlights sparked a cottage industry of shielding and reflectors. France mandated yellow headlights in 1933, and the UK passed anti-glare requirements in 1937.

L.Y.R.’s “Dark Sky Reservation” Shows Dark Skies Entering Popular Culture

Culturally, the group L.Y.R. released a new album in April featuring the moody track “Dark Sky Reservation.” The term originated in environmentalism, referring to regions where light pollution faced discouragement and legal restriction to allow scientists and stargazers to observe the night sky. This marked the second song crossing the show’s radar showcasing cultural impact of dark skies, indicating growing awareness about the special places protecting nighttime environments.

Quick Answers From This Month’s Light Pollution News

What is Bay Lights 360?

“Bay Lights 360” is the official name of the decorative LED lighting returning to San Francisco’s Bay Bridge. Illuminate’s Ben Davis raised $11 million to restore it after the original lights degraded in 2023, and Mark Baker of the Soft Lights Foundation sued, citing a failure to provide mandatory environmental review.

How does artificial light affect bats?

Light reduced foraging activity of Denmark’s Daubenton’s bats by 43% at the source, according to research covered by Light Pollution News. Reunion Island bats showed 62% to 73% increased activity under partial lighting.

What does Illinois SB3037 do?

Illinois SB3037 establishes voluntary lighting standards for commercial buildings through the Illinois Stretch Energy Code. For communities that adopt them, the standards cap color temperatures at 3000K and tie outdoor lighting to 25% of IES standards.

Is headlight glare a new problem?

No. British complaints about bright headlights in the 1930s sparked a cottage industry of shielding and reflectors, and both France and the UK adopted headlight rules in that decade.

What is L.Y.R.’s “Dark Sky Reservation”?

L.Y.R. released a new album in April featuring the track “Dark Sky Reservation,” which Light Pollution News called moody. It was the second song to cross the show’s radar showcasing the cultural impact of dark skies.

About Light Pollution News

You can find all the articles and details over on LightPollutionNews.com. The show audio includes commentary and descriptions that go beyond the written details above. Light Pollution News is a listener-supported show, which means that we take no outside money and wholly rely on the support of our listeners to keep this thing going! See LightPollutionNews.com/Support to learn more.