A study published earlier this year by the U.S. National Library of Medicine as well as the International Journal of Drug Policy, and conducted by the School of Social Work at the University of British Columbia, found that "there was no significant difference between the health of the children living in cannabis grow operations and the comparison group of children".
These findings, according to researchers, "challenge contemporary child welfare approaches and have implications for both child protection social workers and the policymakers who develop frameworks for practice."
Under current law, children are constantly taken away from their parents for growing cannabis, something that this study shows makes little sense, given that a child's health is unaffected; however, no one can legitimately argue that it doesn't harm a child's health and well-being to be unexpectedly removed (sometimes for years, or even permanently) from their parents.
Here's the method that researchers used to come to their conclusion:
The study examined the household, family and individual characteristics of 181 children found living in cannabis grow operations in two regions in British Columbia, Canada. Data was collected on-site on the physical characteristics of the homes, the health characteristics of the children, and their prescription drug history. Comparison of prescription drug use was also made with a group of children from the same geographic areas.
Source: The Joint Blog