Environmental sampling sites

A good example of a prescriptive approach to quality assessment is the protocol outlined in Figure 15.2, published by the Environmental Protection Agency (EPA) for laboratories involved in monitoring studies of water and wastewater. Independent samples A and B are collected simultaneously at the sample site. Sample A is split into two equal-volume samples, and labeled Ai and A2. Sample B is also split into two equal-volume samples, one of which, Bsf, is spiked with a known amount of analyte. A field blank. Dp, also is spiked with the same amount of analyte. All five samples (Ai, A2, B, Bsf, and Dp) are preserved if necessary and transported to the laboratory for analysis. 

Because of the large number of samples and repetitive nature of environmental analysis, automation is very important. Autosamplers are used for sample injection with gc and Ic systems, and data analysis is often handled automatically by user-defined macros in the data system. The high demand for the analysis of environmental samples has led to the estabUshment of contract laboratories which are supported purely by profits from the analysis. On-site monitoring of pollutants is also possible using small quadmpole ms systems fitted into mobile laboratories. 

Assists in identifying appropriate analytical laboratories to evaluate environmental samples (e.g., soil, water, sludge, waste, air) for characterizing hazards at a site. The system factors type of sample, suspected pollutants, user s needs for on-site evaluation, and laboratories locations, capabilities, and ( ualiricalions. 

A sample is representative of a neighborhood measured by the range of correlation. For example, a soil sample could represent a circular area in the field centered at the sample site with a radius less than or equal to the zone of influence. This has always been intuitively obvious to the environmental scientist but now can be described statistically. The zone of influence is defined by the theoretical semi-variogram and is easily estimated from an empirical semi-variogram. 

In environmental health studies conducted near four NPL sites (plus a comparison area for each), ATSDR collected lead concentration data from both environmental media and human body fluids to estimate low-level exposure risk and to document the magnitude of human exposure to lead near those sites. Environmental samples collected at participants homes included drinking water, yard soil, house dust, and house paint body fluids collected from participants included venous blood and urine specimens. For the four sites, mean concentrations of lead in soil ranged from 317 to 529 mg/kg, and mean concentrations of lead in dust ranged from 206 to 469 mg/kg (ATSDR 1995). 

Wong and coworkers118 analyzed fish and other environmental samples (clam, macrophytes, sediments and waters) from areas upstream and downstream from alkyllead manufacturing sites beside the St. Lawrence and St. Clair Rivers, Ontario, and found a clear indication of elevated alkyllead levels in samples near the industries. Most species of fish contained alkyllead compounds with tetraethyllead and triethyllead as the predominant forms. Most fish from the contaminated areas contained 70% or more of the total lead as alkyllead. Average alkyllead levels varied from year to year but declined steadily after 1981. For example, the mean value of alkyllead in carp from the St. Lawrence River decreased from 4207 H g kg-1 in 1981 to 2000 H g kg-1 in 1982 and to 49 Xg kg 1 in... 

For less well defined incidents however, these detection systems may be inadequate. Portable chemical detectors may not be able to be deployed to the site, not detect the agen, or give inconclusive results. Clinical findings may be non-specific, present in an atypical manner, or for example in the case of sulphur mustard, have a latency period that delays firm pattern recognition. Due to the physico-chemical properties of the agent or the time between release and collection, environmental samples may have low agent levels or sufficiently high contaminants to prevent adequate results. 

ABSTRACT This study forms part of a larger multidisciplinary environmental study of the Lower Guadiana River basin carried out by a joint Portuguese-Spanish research team. It describes the mobility of lead in soil profiles taken over varied lithologies of the Iberian Pyrite Belt and the distribution of this metal with the root, stems and leaves of three plant species native to the area (Cistus ladanifer L., Lavandula luisieri and Thymus vulgaris). Results indicate that at all sample sites the mobility of lead is very low. 

Valkenburg CA, Munslow WD. 1989. Evaluation of modifications to extraction procedures used in analysis of environmental samples from Superfimd sites. J Assoc Off Anal Chem 72 602-608. 

RAPID ON-SITE ENVIRONMENTAL SAMPLING AND ANALYSIS OF PROPELLANT STABILIZERS AND THEIR DECOMPOSITION PRODUCTS BY PORTABLE SAMPLING AND THIN-LAYER CHROMATOGRAPHY KITS 125... 

RAPID ON-SITE ENVIRONMENTAL SAMPLING AND ANAL YSIS... 

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