Once the environment is polluted, recovery takes a large amount of energy. In maintaining a sound environment it is important to examine the environment, clarify the causes of damage, and take on appropriate countermeasures for recovery. p Examining the environment means measuring the amounts of hazardous chemical substances designated harmful and obtaining information about their behavior, thereby diagnosing the current state of the environment. For this purpose NIRE has developed tools including the GC-ICP-MS method, which can perform ultra-trace analyses by of individual chemical species that differ in toxicity and behavior, and the crystal unit sensor, which can easily make field measurements. We are also elucidating the behavior of harmful chemical substances that are found at ultra-trace levels by means of in situ filtering and adsorption that take water samples without contamination , and two-dimensional gas chromatography.

NIRE is working on the use of a Quartz Crystal Microbalance (QCM) unit as a chemical substance sensor that takes advantage of a phenomenon in which the change in oscillation frequency of a piezoelectric crystal unit is proportional to the change in weight of a hazardous substance captured on the surface of the crystal unit. NIRE is developing functional molecules that absorb selectively hazardous chemical substances, and methods for modifying them onto crystal units. A method that takes advantage of molecular affinity to detect hazardous chemical substances with selectivity and high sensitivity will make it possible to perform continuous, simple, and fast measurements.

Depending on isomers and chemical species, trace chemical substances in the environment differ in their behavior and toxicity.p To analyze individual trace chemical species, we have developed the GC-ICP-MS method, which combines gas chromatographic separation with plasma mass spectrometric detection. This method is capable of detecting organotin and organomercury in sea water down to the femtogram (10^-15 g) range in absolute amount, and the analysis time can be shortened to less than one-tenth , compared with the conventional method.

Once chemical substances are released into the environment, they disperse through a variety of transport processes. It is necessary to elucidate their pollution of and behavior in the oceans, where they ultimately accumulate. Especially artificial chemical substances like dioxins, PCBs, and endocrine disrupters are found widely throughout the environment, and because they are highly toxic even in minute amounts, scientists are hurrying to determine their behavior in the environment. To analyze these trace substances NIRE is developing an analysis system that combines methods for sampling and analysis. Lowering a in situ filtering and absorption water sampler into the ocean makes it possible to take samples in large quantities, without contaminating them. Two-dimensional gas chromatography-high resolution mass spectrometric analysis of samples allows the selective, high-precision analysis of the desired components.

Dioxins and other substances emitted from facilities such as waste incinerators are recently the focus of attention as hazardous pollutants. These substances are formed in the decomposition and synthesis process that occurs in the incineration of plastics and other materials containing chlorine, and they are released into the environment from smokestacks along with dust in the flue gas. As flue gas temperature falls, these substances are condensed and adsorbed onto particle surfaces, and in the atmosphere they become suspended particulates (particularly PM 2.5, or fine particles with sizes under several µm). However, there is only a limited understanding of the formation and behavior of fine particles with hazardous chemical substances, or the process of their emission.
In order to gather information important to elucidate the chemical toxicity of these fine particles and to control their sources, we are developing a measurement method that sorts according to size the particles emitted by stationary sources.

Volatile organic compounds (VOCs) are a group of organic pollutants emitted from solvent-using industries and exhaust gases. VOCs play an important role in degrading the atmospheric environment of urban and industrial areas by causing tropospheric ozone formation and other hazardous air pollution problems.pIn our research concerning field measurement of VOCs, ambient organic compounds are simultaneously analyzed by a capillary gas chromatograph equipped with a flame ionization detector, an electron capture detector, and a mass spectrometer. Source characterization based on the relative intensities of air pollutants observed is being undertaken to investigate source contributions and to estimate chemical lifetimes.

Carbon dioxide is one of the most important green house gases for global warming, but there still remains much uncertainty how much the substance is uptaken and released in nature. We set up an observation tower in a cool-temperate broad-leaved forest in Takayama City, Gifu Prefecture, to determine how much CO₂ is uptaken and released by the forest ecosystem. Continuous measurement of the CO₂ flux shows that the average annual amount of CO₂ uptaken by this forest ecosystem is about 1.2 t C/ha, but we also found that uptake differs greatly from year to year depending on temperature and insolation in summer season. We also compared our results with readings obtained in forests around the world and are organizing to make up a research network with other similar groups.

It is said that one-third of all anthropogenic CO₂ is dissolved into the oceans, but the actual amounts absorbed now and in the future are unknown because absorption depends on complex processes including ocean currents and the activities of organisms. Plans for sequestering carbon dioxide from power plants in the oceans require that we assess, for example, the behavior of sequestered CO₂ and its effects on marine life. To that end our work on the ship Hakurei-Maru No. 2 includes observations in the Pacific Ocean and the development of models.

The global distribution of greenhouse gases (GHGs), such as CO₂ and methane, must be known in order to understand trends in global warming and to appraise the efficiency of techniques introduced to reduce GHG emissions. For this purpose, the Ministry of International Trade and Industry (MITI) developed a new satellite sensor, the Interferometric Monitor for Greenhouse Gases (IMG), which was launched on the Japanese Advanced Observing Satellite (ADEOS) in 1996. pNIRE has developed new analytical methods to derive greenhouse gas concentrations from spectral data gathered by the IMG sensor. By comparing the observations with results predicted by sophisticated models, NIRE aims to determine the global distribution of emission sources and to better understand the behavior of GHGs in the atmosphere.

NIRE is using a reaction chamber to estimate the atmospheric lifetime and the degradation products of chemical substances with the infrared absorption cross sections of those products. This chamber is made of SUS 304 steel (1 m³, inside walls coated with Teflon), and it has a pressure (10^-6 Torr to atmospheric pressure) and temperature (-40°C to 110°C) control unit, a lighting unit (wavelengths from 170 nm to near infrared), an auxiliary reaction chamber to check heterogeneous processes, and a measuring unit using a long-path cell (variable path length, maximum 60 m) and high-resolution FTIR.