EBS Forensic Studies: identify sources of chemical and biological toxins

 Sampling of groundwater, soil, soil vapor, or indoor air can be part of forensic source sampling.  Passive soil vapor surveys using U.S. EPA Method TO-17 provide a laboratory analysis of volatile organic compounds (VOCs).  The sample modules can be placed on a grid for a rapid property-wide assessment.  Forensic subsurface contaminant maps (one for each target chemical) provide an up-to-date view of conditions.   The source of contamination can frequently be interpreted from the maps.  Expert reports are compliant with Federal Rule 26(a)(2)(B).  

Outdoor air can be affected by a variety of factors and the process of identifying the source of contaminants, particulates or odors is complex.  Sources of possible contaminant or odor producing facilities or environments are first mapped.  Later, chemical, biological, or particulate analytical sample results and other data, such as local air permits or facility notifications are added to the maps to better evaluate the source of air cpollution.  Qualitative odor measurements can also be used in odor studies.

 Flood waters may contain toxic chemicals and human or animal fecal materials as sewers, septic tanks and even wastewater plants can get inundated with flood waters.  PCR and gas chromatography can identify past presence of fecal materials as well as toxic chemicals released during flood events.

Sewer air testing and vapor intrusion (VI) is a specialized sampling activity.  EBS performs sewer air testing to identify possible human exposure related to vapor intrusion issues in buildings.  The sewer-plumbing system can transport volatile organic compounds (VOCs) as well as toxic chemicals associated with illegal drug labs. 

Human fecal bacteria detected near sewer outfall pipes in large adjacent water bodies may reflect a variety of sources, ranging from the wastewater plants, to broken sewer pipes,  to campers or homeless camps near creeks or shores to boaters illegally emptying sewage holding tanks.  

EBS uses analytical testing methods to detect low-concentrations of illicit drug manufacturing residues in indoor air, plumbing-sewer air, and in confined spaces such as vehicle passenger cabins or trunks.  Specific organic compounds detected and the association of chemicals can better delineate the differences between the following clandestine production of illicit drugs:  

• Phenyl-2-propanone (P-2-P),
• Cocaine,
• Heroin, 
• Methaqulone,
• Methamphetamine,
• Phencyclidine, 
• Lysergic acid diethylamide (LSD), and
• Other drugs. not listed.

Haz-Waste dump sites associated with drug labs are dangerous containing numerous chemicals, including:

• Benzene, 
• Toluene, 
• Vinyl chloride, 
• Phosphorous, 
• Potassium cyanide, 
• Potassium permanganate,
• Phosphoric acid, 
• Carbon tetrachloride, 
• Lead arsenate, 
• Mercury, 
• Methyl ethyl ketone, 
• Acetone, 
• Bromine, 
• Cyclohexane, 
• Formic acid, 
• Hexane, and 
• Hydrochloric acid.

Forensic indoor air studies can be used to identify vapor intrusion of air contaminants, dust or particulates, viruses and bacteria, mold and mildew, as well as chemical residuals from former illicit drug operations.  Active air testing relies on specialized air-sampling canisters or active air sampling pumps with the appropriate sampling filter.  In some cases, passive air sampling devices can be used to evaluate specific environmental exposures.   Wipe and tape samples collect contaminants from surfaces such as floors, walls, ceilings, or personal items.  Dust from lead-based paint has been identified in some older homes, and can significantly reduce air quality.  Gas chromatography is used to identify specific volatile organic compounds which might be in indoor air.  Although numerous sources exist for lowering the quality of indoor air (contaminants migrating from below crawl spaces, damaged duct work, dust from lead-based paint, etc.), carpeting, plywood, drapes, and other personal items or building products can emit unsafe vapors, such as formaldehyde, which can be analyzed in the laboratory from collected air samples. 

Examples of commonly available household products that may contain toxins:

• Paints, paint strippers and other solvents
• Wood preservatives
• Aerosol sprays
• Cleansers and disinfectants
• Moth repellents and air fresheners
• Stored fuels and automotive products
• Hobby supplies
• Dry-cleaned clothing
• Pesticides and herbicides

Other products, including:

• Building materials and furnishings
• Office equipment such as copiers and printers, correction fluids and carbon-less copy paper
• Graphics and craft materials including glues and adhesives, permanent markers and photographic solutions.

 As EPA notes, molds are part of the natural environment, and can be found everywhere, indoors and outdoors. Mold is not usually a problem, unless it begins growing indoors. The best way to control mold growth is to control moisture.   EBS can evaluate moisture and water sources within a building which encourage mold and mildew growth.  Once the water sources have been identified, mitigation methods can be designed to stop the water and moisture from entering the building.  Molds have a big impact on indoor air quality.  Sometimes poorly vented crawl spaces, damaged heating, ventilation, and air conditioning (HVAC) ducting can introduce molds, viruses, or bacteria into indoor air.  EBS can collect tape, wallboard or air samples to identify the number and types of molds in the environment.   Viruses and bacteria in the indoor air can also be identified using laboratory methods. 

 In some cases, the events causing water well damage, groundwater or soil pollution, erosion, impacts to indoor air quality, etc. have occurred slowly over time without notice by owners, tenants or others.  Forensic studies are used to reconstruct time-lines and develop a site conceptual model to explain how manufacturing chemicals were released into the environment through a slow, pinhole leak in an underground tank.  Collecting water, soil or other types of samples for chemical analysis helps to identify source of contamination, travel pathways in the subsurface and in the air or buildings, and possible human exposure pathways.  Site conceptual models are used in the forensic environmental science field to describe site conditions.   

 EBS uses forensic studies to identify and mitigate sources of chemical and biological contamination.  Once the sources of contamination have been established, a site conceptual model is used to develop a remediation or mitigation strategy for remediation and case closure. 

Remediation design and implementation using a variety of technologies (extraction, chemical oxidation, bioremediation, and geochemical fixation.  EBS has designed and implemented dozens of remedial actions.  Sometimes, a surgical excavation is the least expensive and quickest route to case closure.  Other subsurface technologies are evaluate based on the client's needs, risk exposure pathway analysis, and regulatory requirements for case closure. 

 Once contamination in soil or groundwater is identified, remediation is usually required by the regulatory agency if the conditions exceed regulatory-accepted contaminant levels or thresholds.  Feasibility Studies and Bench Testing are used to evaluate the potential for success for in-situ chemical applications in the laboratory.  The bench tests evaluate reagent volumes, concentrations, contaminant degradation rates and whether unwanted​ reactions occur that could release metals or other toxins into environment as an unintended consequence of applying reagents to the subsurface.   EBS performs laboratory support services to optimize field results.  EBS performs these types of feasibility studies:

• Enhanced Aerobic Bioremediation,
• Enhanced Anaerobic Bioremediation,
• Co-Metabolic Remediation,
• In-Situ Chemical Oxidation (ISOC),
• In-Situ Chemical Reduction (ISCR),
• Geochemical Stabilization, and 
• Free Product Biosolvent Flushing.