Its been said on these forums before, burning PVC insulation releases heavy metals, dioxin(remember Agent Orange?)
this from a BLM person speaking about folks burning piles of wire on public land out west:
"Dioxins, commonly associated with burnt insulation, are easily absorbed and stored in fat tissue. They are known carcinogens and even low concentrations can cause serious health problems such as impaired immune system and liver function. Long-term exposure to lead, a hazardous waste that is released into soil when copper wire insulation is burned, can cause acute or chronic damage to the nervous system, and high doses of copper can cause liver and kidney damage."
If my neighbor was burning wire i would be seriously pissed.