Throughout our lives, we come into contact with many chemicals and compounds in our environment. Some of these substances, such as pesticides or metals like lead, can be harmful to our health and well-being. Babies and young children are particularly at risk to the harmful effects of these substances, because their brains and other organs are still developing. We are especially interested in understanding exposure to lead in children, because it is very toxic to neurons, which are the cells that make up our brains. Exposure to even a small amount of lead can be bad for our health. 

Lab equipmentOne challenge in looking at how substances in the environment, such as lead, influence child development is that it is difficult to measure these substances in the body. Blood samples are usually needed, but studies that use blood samples can take a long time and are often very costly. Also, multiple blood samples collected at different ages are needed to see how levels of these substances in the body may change throughout the course of a child’s development.

The purpose of this study is to look at the substances children have come into contact with using baby teeth. As teeth grow, enamel and dentine, two of the major components of teeth, form rings called growth rings, similar to the way trees form rings as they grow. As the dentin and enamel form, they “trap” the substances present at that time. By measuring substances in the enamel and dentine of teeth, scientists can figure out what substances children have come into contact with throughout their development. This technique provides the opportunity to look at lots of substances at one time by simply collecting baby teeth that have fallen out or been pulled by a dentist.

In addition to measuring substances found in the environment, scientists can also measure substances produced by our bodies, like hormones or metabolites, using teeth. By measuring certain hormones like cortisol that change in response to stressful life experiences, we may gain clues about exposure to past stressful events and how our body reacted to that stress. 

Baby teeth study sampleNot only can we determine what substances a child was exposed to, but by using the growth rings, we can also determine when they came into contact with them. For example, one mark found in teeth is called the neonatal line because it forms at birth. Using the neonatal line, scientists can determine if a child encountered a substance before birth or after birth.

The Study

We are recruiting parents and their children who are interested in participating in this study. Any child who is 5 to 10 years of age currently living in British Columbia can participate if they have had a tooth fall out, or had a tooth pulled by their dentist. Even teeth that fell out or were pulled a long time ago can be used for this study.
Participation will involve filling out a short questionnaire and mailing the tooth and questionnaire to the BC Children’s Hospital Research Institute. You will be mailed the questionnaire, a tube for the tooth, and a stamped and addressed return envelope. If you are interested in participating, please contact the study coordinator at

This study is supported by the BC Children’s Hospital Foundation and Research Institute.