dioxin

Dioxins are produced by several industrial processes, including the manufacture of paper from wood pulp. (Hemp paper does not involve dioxins.) Several plastics and other petrochemicals also produce dioxins when burned incompletely.

A dioxin compound was the contaminant in Agent Orange that caused a lot of folks in Vietnam to get sick from it.

Dioxins are related to polychlorinated biphenyls, which differ in that they have phenyl rather than benzene rings.

Research done by Paolo Mocarelli has shown that boys who were younger than 19 at the time of the accident went on to have many fewer sons than normal - the usual rate is 51 sons per 100 babies, but in their case, it was only 38 sons per 100. Males older than around 19 were not affected, possibly because they had developed already.

from http://data.intelihealth.com/pcn/menshealth/00283744.htm

   2        3       Dioxins contain one to eight
    \      /        chlorine atoms covalently 
     C----C         bonded at any of the numbered
    /  __  \        locations in the model to the
1--C  (  )  C--4    left.  Closely related to
    \      /        dioxins are furans, in which
     C----C         one ether bond (C-O-C) is 
    /      \        replaced by a direct C-C bond.
   O        O       Also related are PCBs, which 
    \      /        would be two benzene rings
     C----C         attached by a single C-C bond
    /  __  \        and chlorinated with one to 
9--C  (__)  C--6    ten chlorine atoms.  Dioxins
    \      /        with Cl atoms at the 2, 3, 7,
     C----C         and 8 positions are much more 
    /      \        toxic than less chlorinated
   8        7       species.