Environmental Engineering Reference
In-Depth Information
many cases this may be sufficient. However, in the case of results near or
above guideline values, repeated or long-term sampling is desirable. If the
sampling objective is to determine the efficacy of a mitigation measure,
several samples should be collected before and after the implementation of
mitigation measures.
D. Sampling bulk materials/surface contaminants
Environmental sampling to identify/quantify contaminants on or in materi-
als/surfaces is commonly conducted in buildings for such substances as
asbestos, lead, pesticides, PCBs, dust allergens, and biological organisms such
as mold. Many of the same principles/considerations described above for air
sampling apply to material/surface sampling. These include performance
considerations, resource limitations, and sampling considerations such as
one-time sampling, sampling location, and number of samples to be collected.
1.
Bulk sampling
Material sampling and analysis commonly described as bulk sampling is
used to determine the presence and identity of asbestos fibers in building
materials. USEPA requires the use of bulk sampling in the conduct of asbes-
tos inspections in buildings for purposes of asbestos management and for
major building demolition/renovation activities which would disturb asbes-
tos-containing materials (ACM). In the former case, results of bulk sampling
(in conjunction with the assessment of ACM condition and potential for
disturbance) are used as indicators of potential human exposure to asbestos
fibers in buildings.
Bulk sampling is used to identify lead-based paint in/on buildings and
a variety of outdoor surfaces. Bulk sampling for lead is conducted using
nondestructive
techniques such as X-ray fluorescence and paint chip
and soil analysis using atomic absorption, inductively coupled plasma, and
anodic stripping voltammetry.
Bulk sampling is also conducted on mold-infested materials to identify
mold types as well as their relative abundance. Samples are dispersed in a
liquid medium and plated out on nutrient agar plates.
in situ
2.
Surface sampling
Surface sampling is conducted by vacuum or wipe methods to ascertain the
degree of contamination by lead, pesticides, plasticizers, PCBs, and allergens.
It is commonly used to determine the efficacy of remediation measures.
Surface sampling is commonly conducted for lead in house and other
building dusts. Because of the very serious health hazards associated with
lead exposure, significant efforts have been made to evaluate and use surface
sampling techniques. These include vacuum and surface wipe sampling.
Because of its longer history of use and observed significant associations
with blood lead levels, most lead sampling of household dust is conducted
using wipe sampling. Wipe sampling is recommended by USEPA and the
