One of the concerns that I have had to deal with is cattle dipping vats.
Not only petroleum chemicals but arsenic. A soil analysis was done for the
USDA Forest Service that sampled the soils around the dipping vats in the
Southeast.  In areas like Arkansas with steep terrain and rocky soils with
plenty of runoff, the arsenic was essentially undetectable.  In areas like
Louisiana with mild to flat terrain and deep soils, there was still
measurable arsenic.

On Thu, May 16, 2013 at 1:04 PM, Jerry Schaefer <[log in to unmask]
> wrote:

> Here in San Diego the archaeologists and supervisors who come on site
> where there are HazMat have to be 40-hour HAZWOPER certified (and up to
> date with 8-hr refreshers).  Porous historical artifacts like bricks and
> bone, and iron are usually contaminated with lead and other heavy medals
> and avoiding inhalation/injection is pretty easily done.   Sometimes we do
> the washing on site when the HazMat engineers recommend it.  We do have to
> go to Tyvec, respirators, etc, (Level C) and decontamination when the
> levels exceed maximum allowable exposure but that is pretty rare.  When
> materials are contaminated with petrochemicals we usually record in the
> field and discard. If there are things we want to keep then we leave them
> on site until the petrochemicals vaporize, and there is usually a HAZMAT
> lab to test materials (and us) to make sure that exposure levels stay to
> allowable levels. There are chemical solvents and detergents you can use on
> site as well.  Non-technical approach: if
>  the artifacts stink of gas they don't go back to the lab. Exposure in the
> air usually does the trick.  Monitoring or excavating a grossly
> contaminated site that reeks of petrochemicals is something we avoid.  Who
> wants to come on to a site and dig  with a Level A suit and oxygen tanks.
> General rule of thumb, if you are smelling petrochemicals then you should
> not be there, although smell tests are not the recommended method of
> detecting hazardous vapors.  Check with OSHA for maximum allowable
> exposures. Sometimes just allowing an excavation area to air out can get
> you there.  I would say generally, work with the HazMat people on site to
> figure out what to do.
>
> Regards,
>
> Jerry Schaefer
>
> ASM Affiliates, Inc.
> 2034 Corte Del Nogal
> Carlsbad, CA 92011
> 760-804-5757 (office)
> 760-804-5755 (fax)
> http://www.asmaffiliates.com/
>
> --
>
Smoke Pfeiffer
The welfare of humanity is always the alibi of tyrants.- Camus