TACKLING LIGHT POLLUTION: A Growing Environmental and Health Concern

The Consumers Association of Penang (CAP) wishes to highlight an increasingly pressing issue: light pollution. Light pollution refers to excessive or misdirected artificial lighting that interferes with the natural darkness of the night sky.

One of the most basic services provided by local governments is proper nighttime lighting. It plays an essential role in ensuring public safety and security on roads, highways, and in public spaces, while also acting as a deterrent to crime by improving visibility for motorists and pedestrians alike. However, with the expansion of cities and the spread of artificial lighting across sprawling suburbs and urban areas, light pollution is becoming a serious environmental concern.

Streetlights, pathway lights, electronic billboards, shopping malls, industrial sites, buildings, outdoor fixtures, and the powerful floodlights used in sports centres, fields, and stadiums all contribute to the bright, hazy glow that obscures the natural night sky. This excessive illumination does not only affect the visibility of the stars but also disrupts ecosystems and impacts human health.

Scientific studies show that artificial light at night has harmful and sometimes fatal effects on a wide range of wildlife, including plants, birds, insects, amphibians, and mammals. Many species rely on the Earth’s natural light-dark cycle to regulate critical life functions such as reproduction, navigation, foraging, sleep, and protection from predators. Migratory birds, for example, can become disoriented during peak migration periods, leading to fatigue, collisions with buildings, and even population declines.

Sea turtles face a particularly grave threat from artificial lighting. Brightly lit beaches can discourage female turtles from nesting. More tragically, hatchlings, which instinctively head towards the brightest horizon—typically the ocean reflecting the night sky—are often lured inland by artificial lights. This disorientation increases their vulnerability to predators, exhaustion, and dehydration. Artificial lighting on human-occupied beaches is now recognised as one of the most significant conservation challenges for sea turtle populations.

Similarly, bats are sensitive to light pollution. Light near their roosts can delay their emergence at dusk, the time when insect prey is most abundant. In some cases, bats may abandon their roosts altogether, or worse, become trapped inside, starving to death as they wait for darkness that never arrives.

Insects, too, are affected. Fireflies’ bioluminescent signals are dulled or disappear entirely in areas with outdoor lights or where indoor light spills outside through windows. Even a brief flash of car headlights can interrupt their mating signals. Furthermore, research suggests that even diurnal insects – those active during the day – can suffer from nighttime light exposure.

While habitat loss, pesticide use, invasive species, and climate change are well-known contributors to the global decline in insect populations, artificial light at night is an often-overlooked factor. A recent study, “Light Pollution is a Driver of Insect Declines,” underscores the role of light pollution in the ongoing loss of insect biodiversity.

Light pollution also disrupts predator-prey dynamics. Artificial lighting can help predators locate prey by eliminating the cover of darkness that prey species rely on for protection. As a result, prey animals may avoid migrating or feeding under illuminated conditions, restricting their access to essential food and resources.

Humans are not immune to the effects of light pollution. Exposure to artificial light at night disrupts the circadian rhythm, suppressing the production of melatonin, a hormone critical for sleep regulation. This disruption can lead to sleep deprivation, fatigue, headaches, stress, anxiety, and an increased risk of serious health conditions such as obesity, cancer, cardiovascular diseases, and mental health disorders.

Dr Muhammad Syazwan Faid, a researcher on light pollution and senior lecturer at the University of Tun Hussein Onn Malaysia, has proposed several measures to mitigate light pollution. These include replacing blue-rich white lighting with low-density, warm-coloured LEDs with lower correlated colour temperatures (CCTs); installing motion sensors and timers on streetlights; conducting regular audits to identify and correct overlit or poorly directed lighting; and using fully shielded fixtures that direct light downward to reduce glare and skyglow.

Malaysia currently lacks a comprehensive lighting or planning strategy to manage unregulated artificial lighting. CAP is therefore heartened by the news that a Light Pollution Guideline is in development, with contributions from stakeholders including local authorities, academics, industry players, and astronomy communities. CAP eagerly anticipates the completion of this guideline, expected by 2026, as a critical step forward in addressing the impacts of light pollution.

Mohideen Abdul Kader
President
Consumers Association of Penang

Letter to the Editor, 23 July 2025