Date:         Wed, 18 Jun 1997 13:19:03 -0700
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         "Dan R. Greening" <greening@zuni.likeminds.com>
Subject:      Re: burning plastic

Martha,

Some obvious facts about burning plastics and the resulting organochlorides.

1. No large modern cities burn trash at low temperature due to pollution
issues, and all major cities use landfills, ocean dumping, or
high-temperature burning (most using landfills).  This is because unburned
hydrocarbons are implicated in cancers, particulates in asthma and
emphesema, and low-temperature oxides of plastics, such as dioxin and other
organochlorides, are strong carcinogens.  High-temperature burning of
plastics is actually not as big a deal because they reduce to HCl
(hydrocloric acid), water, NO2, CO2, and other less reactive compounds.
Hydrocloric acid and NO2 are bad, but not as bad.  Low temperature burning
of plastics (such as in a campfire) is extremely bad.

2. Unburned hydrocarbon output is extremely low in modern automobiles due
to catalytic converters.  Old busses are a different story.  However, autos
do not produce organochlorides as far as I know.  My strong feelings about
burning plastic come primarily from the fairly well-known toxicity of
volatile organochlorides.

3. If I am particularly concerned about my personal exposure to
carcinogens, being that our bus was downwind from the fire, I think
comparisons with automobile pollutants are somewhat specious.  Simply the
awful smell of burning plastic, which was noxious at our bus about 100 feet
away, is cause enough to reconsider burning plastic.  It's not fun for me.

Hopefully a chemist will respond with more detailed information.  I did a
simple web-search for this information and it was slim pickings.  It's
easier to find computer science research than chemical research on the web.
 However, here's some background:

>From http://www.mcspotlight.org/media/reports/wenchlorine.html

---

In making organochlorine products, highly toxic by-products such as dioxins
are inadvertently made at the same time and accumulate in the same way as
PCBs in our bodyfat and in the environment generally. Similar major
pollution problems also arise when these chlorinated products such as
plastics and solvents are burned or incinerated as rubbish. The resulting
polluted air affects the surrounding area, falling on agricultural land and
accumulating in the food chain, putting food such as dairy products at risk
from high levels of dioxins. 

Studies in the US have shown that the presence of dioxins and PCBs is
linked to nervous system damage in babies, with effects on memory and
co-ordination. WEN's report, Chlorine, Pollution and the Parents of
Tomorrow assesses the levels of dioxins and PCBs in Britain and concludes
that similar effects may be occurring in between 1% and 8% of babies in
this country. 

International bodies and scientific institutions worldwide are calling for
chlorine phase-out. In February 1994, President Clinton announced a
strategy for the phase-out of chlorine in manufacturing; many towns and
cities in Europe have banned PVC and the amount of chlorine used to bleach
paper has fallen dramatically over the last few years. Chlorine has such a
huge presence in our industrialised society, but now awareness is leading
to the development of alternatives. 

----

Given the significant carcinogenicity of organochlorides, and the
incredibly low satisfaction (negative satisfaction for downwind me) derived
from burning plastic, it seems mean-spirited to insist on it.  

Think of it in terms of risk/reward.  Magnesium and aluminum oxides, as we
have discussed before, are threatening only as normal burned particulates
(risk), but burning engines is fun (reward).  Burning plastic provides slim
entertainment (and actually alienates me), and is significantly more deadly.  

Therefore, the risk/reward ratio is high, and I say we stop burning plastic
at CCC outings.

Regards,


Dan Greening, Ph.D.     CTO, LikeMinds, Inc.       10164 Parkwood Dr. Suite 8
greening@likeminds.com  408-996-1115 fax 865-0571  Cupertino, CA 95014
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