After undergoing the catastrophic phase of the 2 world wars, soil and water contamination has become a major problem faced by the countries globally. It has been estimated that there are hundreds of explosives-contaminated sites in the United States, and even a greater number in Europe and Asia. TNT, Rapid Detention Explosive (RDX) and High Melting Explosive (HMX) are the most commonly found explosive contaminants found in soil and water which are the materials majorly used by the military forces. Even after the 80 years of World War I, the soil samples obtained from Belgium were containing, substantial amount of contamination, mainly by lead, copper, arsenic and nitro aromatic metabolites such as 1, 3-dinitrobenzene. Managing sites contaminated with energetic materials has also become an international problem shared by many countries.

Here are 6 Severe Cases of Soil Contamination:

• Each year in the EU, 3 billion tons of solid wastes are thrown away and some 90 million tons of them are hazardous.
• Soil from the Louisiana Army Ammunition Plant (LAAP), the U.S in 2007 was contaminated with 10000, 1900 and 900 mg/kg of TNT, RDX and HMX, respectively.
• More than 100,000 tons of 2,4,6-trinitrotoluene were produced at the former ammunition site Werk Tanne in Clausthal-Zellerfeld, Germany
• Explosives were found in the groundwater of the Milan Army Ammunition Plant.
• The Pantex Plant used by the U.S. Army during World War II (1942-1945) for loading conventional ammunition shells and bombs is another case of highly contaminated site.
• In the US, the army alone has estimated that over 1.2 million tons of soils have been contaminated with explosives, and the impact of explosives contamination in other countries in the world is of similar magnitude.

Hazardous Impacts of Explosives in Soil & Water:

Due to improper handling and disposal techniques, the explosive contaminants and their derivatives have polluted environment to levels that threaten the health of humans, livestock, wildlife and, entire ecosystem. Unexploded ordnance (UXO) from military operations worldwide also poses a serious environmental threat due to the release of toxic substances from the corroding ordnance. In addition to the risks associated, these also possess a potential for an accidental detonation. Ingestion, inhalation or dermal absorption of contaminated soil and water by a human body could lead to diseases like geohelminth infection, cancer, hookworm disease, and podoconiosis. Also, it could lead to congenital anomalies and impotency.

As explosive contaminated soil and water is a serious threat to human life and entire ecosystem, numerous solutions are available in the market to identify and remediate explosive-contaminated soils and waters. Electronic Sensor Technology, Inc. (EST) based in California provides one such solution by its portable sensor technology called zNose®. This electronic nose uses gas chromatography (GC) and Surface Acoustic Wave (SAW) to give complete profile of every possible kind of odors and chemicals in less than a minute. zNose®’s gas detection voc capabilities can be applied to chemical analysis of air, water and soil for odor management and remediation projects.

The Vapor Analysis System of zNose®, used in zNose® provides a quantifiable response to multiple types of explosives simultaneously. Extracts of 2,4,6-trinitrotoluene (TNT), hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), 2,4-dinitrotoluene (2,4-DNT) and 2,6-dinitrotoluene (2,6-DNT) from soil or water were easily obtained in minutes allowing the system to operate under field conditions.

The use of the device for the detection of explosive has shown that, it can also be used for rapid screening of soil and water for explosives at the mg/kg and water at the mg/l concentration level. The instrument can perform an analysis in just 1 minute after injection of the sample. The fast response of the instrument also qualifies it as an Electronic Nose with the advantage that it has stable sensors that do not drift and do not require constant calibration.

By combining SAW detectors with high-speed temperature programmed chromatographic columns, specificity over a wide range of vapors at the part per billion level in near real time (< 1 minute) has been achieved. The GC/SAW offers the advantages of a low-cost solid state detector and the specificity of a temperature programmed GC column.

zNose®’s Assistance to US EPA

Expended ammunition and waste from the manufacture of military ordinance has led to the dumping of enormous quantities of explosives onto military bases for the past 100 years. This severe dumping has made explosives in soil and water, a significant problem for the U.S. government and the populous at large. The U.S. Environmental Protection Agency (EPA) to offer a clean and safe environment has undertaken the task of remedying the contaminated sites by using new technologies, under the Environmental Technology Verification (ETV) Program. Electronic Sensor Technology (EST) participated in two of these programs in the past several years. The first was the detection of polychlorinated biphenyls (PCBs) in soils and the second was the well head monitoring of volatile organic compounds (VOCs) in groundwater.

Furthermore the zNose® was used in a blind test sponsored by the U.S. EPA’s ETV program and was qualified as an acceptable technology to participate in a comprehensive field study of explosives in soil and water. The zNose® volatile organic compound detector provides a parts-per-trillion sensitivity and can detect odors and chemical vapors effectively and efficiently.

Since the protection of the environment is nowadays one of the highest priorities in most of the countries these days, the modern detection device like zNose® would offer a great help in protecting the ecosystem of Earth. Also, it would put enormous constraint not just on the advancements in the explosives manufacturing industry in any country, but also on the further degradation of soil and water.