Across Lawrence, more than 1,500 incandescent light bulbs already have been switched out for compact fluorescent lights as part of an intrastate energy competition with Manhattan.

In the Take Charge Challenge competition between Lawrence and Manhattan, residents are encouraged to reduce their energy use. The winning community will receive $100,000 to help fund an efficiency project, money that comes from the American Recovery and Reinvestment Act.

Using compact fluorescent lights is one way to cut back energy use. And while CFLs offer a great way to save money and conserve energy, many people have questions about just how safe and practical they are.

We asked experts in Lawrence to answer some of the most commonly asked questions.

Do CFLs contain hazardous material?

Yes. On average, a CFL contains about four milligrams of mercury, which is sealed within the bulb’s glass tubing, according to the Environmental Protection Agency. In comparison, the amount of mercury is less than 0.01 of the amount found in an old mercury thermometer.

At high levels, exposure to mercury can harm a person’s brain, heart, kidneys, lungs and immune system. In newborns and young children, the mercury can affect the nervous system, which makes a child less able to think and learn.

The risk of a small mercury spill has to be weighed against the amount of energy savings the bulbs provide, said Eileen Horn, the sustainability coordinator for Douglas County and the city of Lawrence.

“In general, all new technology has costs and benefits,” Horn said.

How do I dispose of CFLs?

Just like paint and household cleaners, CFLs should not be thrown in the trash and taken to landfills, said Kathy Richardson, operations supervisor for the city of Lawrence’s Waste Reduction and Recycling Division.

Instead, Richardson said, they can be recycled through the city or at some local hardware stores.

As part of the city’s Household Hazardous Waste Program, residents can schedule an appointment to drop off CFLs by calling 832-3030. In Lawrence, Home Depot, 1910 W. 31st St., and Cottin’s Hardware and Rental, 1832 Mass., also accept household CFLs.

What do I do if I break a light bulb?

Since CFLs contain a small amount of mercury within the glass tubing, if a bulb breaks some of the mercury is released as mercury vapor. The broken bulb can continue to release the vapor until the material is cleaned up and removed from the residence.

The EPA offers these guidelines:

l Before the cleanup, have people and pets leave the room, and air out the room for five to 10 minutes by opening windows and doors. Also, shut off the heating or air conditioning system.

l During the cleanup, make sure you collect all broken glass and visible powder. Place the cleanup materials in a sealable container.

l After the cleanup, promptly place all the bulb debris and cleanup material outdoors in a trash container or a protected area. Avoid leaving any bulb fragments or cleanup materials indoors. To dispose of the broken bulb, contact the city’s Household Hazardous Waste Program at 832-3030.

If possible, continue to air out the room where the bulb was broken and leave the heating or air conditioning system shut off for several hours.

If CFLs contain mercury and incandescent lights use more energy, which is better for the environment?

When CFLs break or are improperly disposed of, small amounts of mercury are released into the environment. However, the EPA calculates the amount of mercury from CFLs is far less than the amount of mercury that would be released from coal-burning power plants to provide electricity to the more inefficient incandescent lights.

I don’t like the harsh blue lights that CFLs emit. Do I have another option?

Yes. According to Linda Cottin, of Cottin Hardware and Rentals, technology has come a long way for CFLs. Manufacturers have produced a soft white CFL bulb that emits light similar to an incandescent bulb.

“With the yellow light, you won’t notice too much of a difference,” Cottin said.

Consumers can also buy a bluer light that manufacturers designed to mimic daylight, which is suppose to be more calming and easier on the eyes. Consumers tend to prefer the soft yellow light, Cottin said.

Where can I use CFL bulbs?

Manufacturers of CFLs are making lights that work not only in lamps but for a home’s recessed lighting, floodlights and spotlights. Buyers can find lights of different shapes and sizes for kitchens, bathrooms and outside.

However, manufacturers still have a ways to go, Cottin said. Here are some of CFLs’ limitations:

l CFLs can be used for dimmer lights both inside and outside, Cottin said. But they dim down to about half the full light, as opposed to incandescent lights that can go almost all the way down to dark.

l Manufacturers also have made CFL bulbs for chandeliers. But, Cottin said if the bulbs aren’t covered, they aren’t the most beautiful bulbs.

“Every year we get a little bit better, but we aren’t quite there yet,” she said.

l For outdoor lighting, Cottin said to be prepared for CFLs to take a few minutes to fully illuminate. Most of the time, that shouldn’t be a problem. But because of the slower turn-on time, Cottin doesn’t recommend using CFLs for motion sensors to scare away animal predators.

Do CFLs really save you money?

No doubt about it, CFLs are more expensive to buy. At Cottin Hardware, a box of four costs $9.99. In comparison, a box of four 60-watt incandescent bulbs runs $2.29.

However, the CFL bulbs last for 12,000 hours while the incandescents have a life of a 1,000 hours. Along with having to be replaced far less often, CFLs save a lot in energy costs. In the first year, a CFL can create $6.86 in energy savings, and $37 over the five-year lifetime of the bulb. And, those numbers don’t include the cost of having to buy new incandescent bulbs to replace the ones that have burned out.