Monte Carlo Simulations for Human Health & Ecological Risk Assessment

Dear R Experts!

I would really love to perform probabilistic risk assessment for human
health and ecological using Monte Carlo. I am knowledgeable in the risk
assessment part but have no idea how to incorporate Monte Carlo simulation
using R.  Is there anyone out there in the wide wide world of R who has
actually used Monte Carlo for this type of risk assessment and kind enough
to show me the way?

Many thanks in anticipation!

Janh