Hello. I'm Lisa Hepp, and I'm an epidemiologist with the Institute for Global Tobacco Control at Johns Hopkins Bloomberg School of Public Health. In this video we'll be discussing collecting saliva samples as a method to measure personal exposure to secondhand smoke. We'll be discussing the materials and procedures necessary to collect samples. 

When we go into the field, we prepare collection kits ahead of time to help better keep us organized. The collection kit for saliva contains gloves, salivettes, which are a tube plus cotton pads, hand sanitizer, paper towels, cooler with ice packs, tape, and weather-proof labels. Wearing gloves is both for you, the field worker, and the participant. It will help prevent any possible contamination with the salivette, but also minimizes any contact with the participant's saliva. 

This is a salivette. It is basically made of three components. The inner tube, cotton roll, and a centrifuge tube. It's best to label the tube with the participant's study number before collecting the sample. Write the number on a weather-proof label and adhere it to the tube. Adding a piece of tape can help keep the label on once in the freezer. The weather-proof labels are important as they are designed to withstand moisture. 

Once the samples are in the freezer, they may gather ice or frost on the outside. If the label is not weather-proof, it will quickly deteriorate once taken out of the freezer and the ice is wiped away. Then you won't be able to match the sample up to any information gathered from the participant. For example, if they were a smoker. 

First, I'm going to ask you to clean your hands just a little bit. 

Have the participant wash their hands with antimicrobial hand sanitizer before handling the cotton swab. Inform the participant to remove the cap of the sample tube and place the sterile swab directly into his or her mouth near one side. 

And you want to take out that and put it underneath your tongue. 

Caution the participant to minimize contact of the swap with their hands. Direct the participant to gently chew in order to facilitate saliva production for approximately two minutes, ensuring not to directly chew on the swab. Instruct the participant to expel the cotton swab directly, without handling it, back into the labeled sample tube once it is soaked with saliva. 

Recap the sample tube, ensuring the cap is tightly in place. Place the sample tube in a portable cooler with ice packs for temporary storage and transportation until the end of the collection day. At the end of the day, the saliva sample should be moved to a minus 20 degrees Celsius freezer, if possible. 

Once all the samples have been collected, they will need to be shipped to the lab. Depending on where your lab is, this may require special shipment. If the samples were placed in a minus 20 degrees Celsius freezer, and are frozen, they should remain that way. Thus, you'll have to ship them with dry ice. 

We've now completed our brief training guide on collecting saliva to measure personal exposure to secondhand smoke. For additional information, please refer to our website for other resources. Thanks for viewing this video, and remember, there is no safe level of a secondhand smoke exposure.