The Building Where It’s Never Dark: Unconventional Advertising and Light Pollution in the Heights of Mexico City

For the past five years, residents of the Citaltepe building have not been able to sleep well. Every night, the bright and persistent light from a billboard installed in front of their building in the Villa Panamericana neighborhood floods their apartments. The ads projected on the giant screen change every 15 seconds, casting everything in their homes in vibrant colors: bright yellow, intense pink, or blinding white. They have covered windows, changed routines, and attempted—unsuccessfully—to rest peacefully under a glow that never turns off, impacting their health and environment. This invasion is more than just a story of the Citaltepe; it is part of a growing problem of light pollution spreading throughout the capital, highlighting the lack of effective regulation on outdoor advertising in Mexico City.

In the building, which borders the Periférico Sur, people of all ages and different routines live, but they share a common discomfort. From the ground floor to the fourth floor, residents agree that their rest has been affected since the screen was installed. Edson Moysen, 24, moved into this apartment in 2020, not imagining he would cohabit with a light that does not distinguish between day and night. Initially, his room faced directly onto the billboard. “I couldn’t sleep. I had to move to a different room,” he recounts. On the ground floor, Norma Sánchez, 69, lives with her sister, who suffers from a chronic illness. “She is the most affected. She is fed up. She doesn’t rest as she should,” she says resignedly. Sánchez is convinced that the impact goes beyond mere annoyance and points to a building two streets away that reflects the light from the same billboard.

Enrique Gaona, 52, shares that his room does not face the advertisement, but the light slips into the house, and every night he has to close all the doors to fall asleep. For Kateri Pérez, 60, the situation is unbearable. “It’s like sleeping with the lights on. It’s unnatural,” she says. In her home, three people are affected, including her daughter, who has to sleep with an eye mask. However, she refuses to install special curtains: “On top of suffering from this problem, why do I have to pay to cover it?” she questions. The neighbors ignore the projected advertisements and are unaware of the brands being advertised: “They tend to be banks, apps, or movies; I prefer not to see it,” Pérez states.

This newspaper contacted the advertising company, JCDecaux—one of the largest outdoor advertising companies in the world—which responded to the residents’ complaints, asserting that the billboard complies with the necessary permits and that the screen shuts off between 1:00 AM and 5:00 AM, without exceeding 1% of its maximum brightness at night. However, the residents of Citaltepe deny this: “I don’t have the equipment to measure the light projected by the advertisement, but it’s on 24 hours a day,” Gaona assures, and the others agree. Pérez adds, “According to those rules, do we only have the right to four hours of sleep?”

Prolonged exposure to artificial light has severe health consequences primarily related to sleep disorders, but also affecting issues as diverse as obesity, depression, diabetes, and hypertension, explains José Roberto García Chávez, an expert in light pollution from the Universidad Autónoma Metropolitana Unidad Azcapotzalco. Furthermore, this type of pollution impacts the environment, vegetation, and animal species by disorienting their natural cycles of reproduction, feeding, migration, and rest and affects astronomical research, he adds. According to García, more than 80% of the population in Mexico lives under highly polluted night skies, while legislation to regulate it progresses slowly.

Lack of Regulation

Although the company advertising in front of the Citaltepe building asserts that the screen has the necessary permits, consulted lawyers indicate that regulatory compliance does not always guarantee the protection of the environment or residents’ rights. “The fact that a structure is in the official catalog does not mean it cannot violate other regulations, such as those concerning environmental impact or residential protection,” explains legal consultant Beatriz Cuéllar Morales.

According to the regulations of the Current Outdoor Advertising Law in Mexico City: “Electronic screens must adjust automatically to ambient brightness and cannot exceed 325 nits between 6:00 PM and 6:00 AM. Projected images must last between 18 and 30 seconds, cannot have white backgrounds, nor show videos or moving lights. They must not emit sound or change in intensity while the message is fixed.”

However, compliance verification is often weak or non-existent. “Neighbors have the right to demand technical inspections and to file formal complaints if their quality of life is compromised,” states Víctor Manuel Dávila Barraza, a professor at the Faculty of Law of the National Autonomous University of Mexico. “In light of the gaps in the law, human rights must be defended. Even if it is determined that the advertisement conforms to regulations, the fact that it affects the health of the residents is enough to demand regulation,” he adds.

The Foundation for the Rescue and Recovery of Urban Landscapes has been fighting irregularities in outdoor advertising in Mexico City for years. Its president, Jorge Negrete, reports that companies have started using bright billboards to maximize the benefits of a single installation. “It is much more profitable for them to place a screen because this way they can have many ads in one place,” he declares. This type of advertising is also associated with traffic accidents, as it distracts drivers and cyclists, Negrete explains.

Since its creation, the foundation has worked with various neighborhood communities and has successfully closed or uninstalled all types of irregular advertising, such as rooftop billboards. Negrete recounts that the vast majority of cases are ignored, and responses from companies or the Secretariat of Planning, Territorial Order, and Metropolitan Coordination of Mexico City—responsible for managing advertisements in the capital—are rare.

In the meantime, in the Citaltepe building, night still does not fully arrive. For its inhabitants, sleeping with closed curtains, eye masks, or barricaded doors is not a solution, but an adaptation. A regulatory framework exists, but its enforcement remains a pending obligation.