A person sprayed with a dioxin, how long would it take for a dna change? Instant or over time? Would that person having children afterwards pass on any(if any) dna changes?
Studies on model organisms suggest effects begin quickly, within 6-8 hours of exposure. Rat studies suggest liver absorption of dioxin reaches a maximum from 8-24 hours, with Cytochrome P450 protein expression levels peaking afterwards. Another study uses a comet assay that measures DNA damage after six hours of dosing, and damage is tied to dose level.
Epigenetic changes to sperm and eggs are heritable, passed along to offspring. These result from histone deacetylation and methylation, which in turn change how DNA are packed and unpackaged for protein expression, and change expression itself.
A summary article on epigenetic dioxin (TCDD) toxicity suggests that there are specific effects on protein expression involved in embryonic development in model organisms, which result in birth defects and immune system damage.
In addition to controlled lab experiments on rats and mice, the United States of America conducted a massive, uncontrolled science experiment on humans, dropping dioxin in great quantities on millions of Vietnamese civilians during the Vietnam War. Children of exposed victims suffered spinal bifida and other birth defects. US military exposed to dioxin in the course of deploying this chemical weapon also had children suffer greater rates of similar birth defects.