When mass production of fluorescent light bulbs began in 1940, they were hailed as an energy-efficient improvement on the incandescent bulb. Fluorescent lighting has long been widely used in classrooms for all ages, including preschoolers and college students. Researchers have attempted to determine if long-term exposure to fluorescent lighting could be a factor in a child’s behavior and academic performance.
A fluorescent bulb emits light when gases and a small amount of mercury are ionized inside a glass tube coated with phosphors. A ballast in the tube regulates the intensity of the flow of electricity to keep the bulb from overheating. These bulbs are preferred for interior lighting because they are cooler than incandescent bulbs and last considerably longer. Concerns about the bulbs stem from the flickering that occurs at high frequencies and when the ballast begins to fail. Some educators and doctors worry that daily exposure to fluorescent lighting can have adverse effects on learning and overall health.
Since the early 1970s, researchers have looked for a connection between fluorescent lighting and behavior. In 1973, researcher James Ott compared the behavior of Florida schoolchildren studying in a room lit by traditional fluorescent bulbs with that of a group in a room lit by newly developed full-spectrum bulbs that mimicked natural daylight. He concluded that children were more attentive in the room lit by the full-spectrum bulbs. Another researcher -- K. Daniel O’Leary, who conducted a separate study at the same time -- found little if any variation in behavior. Ellen Gragaard at the University of Nevada studied groups of first-graders in 1993 and found that not only did they stay more focused under full-spectrum light bulbs, but their blood pressure dropped 9 percent.
Students with autism and attention deficit hyperactivity disorder (ADHD) are particularly sensitive to environmental stimuli in the classroom. Ott's study found that students diagnosed as hyperactive appeared to show improved attention under full spectrum lights. In a paper published by Kansas State University in 2010, Emily Long reported that the bright light, flickering and buzz of worn fluorescent bulbs increases repetitive motions and agitation in autistic children.
Researchers and teachers have concluded that some children are attentive and engaged in softly lit spaces while others need bright light to stay focused. In 1982, St. John's University researcher Jeffrey Krimsky found that fourth-graders who showed a preference for bright or dim light performed better at reading tasks in their preferred environment. A 2002 study by the Heschong Mahone Group for the California Energy Commission found that the amount of natural light from windows and skylights has a measurable positive impact on student work and behavior. The task has changed from figuring out how all children can learn under the same lights to designing spaces that can support different degrees of illumination.
The Future of Fluorescents
As government officials struggle with energy costs and environmental concerns, advanced lighting products are being considered for new construction. Alternatives to traditional fluorescent bulbs have been introduced. A technical brief published by the California Energy Commission in 2008 describes a classroom in Antelope, California, equipped with high-efficiency fluorescent lights that can be controlled for brightness and localized on a spot in the classroom. Another school district in Illinois has installed light-emitting diode (LED) lights in their exterior spaces. How children will learn in those settings has yet to be determined.