Environmental Risk Assessment for Chemicals
Homepage: http://www.nies.go.jp/risk/index-e.html
In our daily lives we are assisted by the more than 100,000 industrially produced chemicals in use today. In addition to these, many chemicals such as dioxins are unintentionally generated and released into the environment. We are surrounded by this plethora of chemicals on a daily basis, some of which may affect human health and ecosystems. The reduction of environmental risk from such chemical substances has become an important issue for the future of humanity. NIES is studying the many types of chemical pollution around us in order to identify ways to properly assess and manage the risks, and to find ways that humanity can coexist with chemical substances.
Detecting Environmental Change
In order to manage environmental risk properly, it is essential to investigate
whether or not any abnormalities have occurred in human health or the
ecosystem from a given substance.
NIES is conducting ongoing field studies in Lake Kasumigaura, and has
confirmed rapid changes in the species and numbers of living things. Some
of the changes in the biota could be explained as the result of changes
in fishing methods, invasion of foreign species or changes in the structure
of the lake. However, the decrease in benthic life such as the bivalve
clam Anodonta woodina japonica cannot be explained by those factors. Hence,
it is essential to clarify the causes of these changes, including the
impacts of chemicals. In the Sakura River, which flows into Lake Kasumigaura,
we are using organisms such as the freshwater shrimp to monitor pollution
from agricultural chemicals. We have found that even miniscule concentrations
of these chemicals result in significant growth impediments, behavioral
changes and sometimes death in a variety of living things.
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Bio-monitoring of the behavior of freshwater
shrimp (Pratya compressa improvisa) using actual river water. When polluted
by agricultural chemicals the shrimp is continually active. Growth impediments
also occur.Clarifying the Impacts on Human Health
At the point that impacts have been discovered on human health or the
ecosystem, it becomes necessary to clarify the causes and mechanisms involved
and to evaluate the environmental risks. For that, it is necessary to
investigate the dose-response relationship: What dose of chemical results
in what impacts?
In terms of health effects, we are conducting epidemiological studies
on human populations, as well as using laboratory animals such as mice
and rats. At NIES we have been using sensitive testing methods to clarify
health impacts and mechanisms, such as the use of animals created through
genetic engineering that may lack a certain protein or be susceptible
to a certain disease.
Based on these results, it is possible to study the dose-response relationship.
However, individuals may have different levels of susceptibility to chemicals;
if this is not taken into account it is not possible to prevent impacts
on the most sensitive people. To address this concern, we are developing
risk assessment techniques that take susceptibility into account, using
the latest genetic analysis techniques to clarify which genetic factors
control susceptibility. 
Toxicity testing of
hazardous chemicals using metabolic gauge.
Clarifying Impacts on Ecosystems
International collaboration is essential with regard to testing techniques
to assess the environmental impacts of chemical substances. The Organization
for Economic Cooperation and Development (OECD) has prepared guidelines
for the use of various types of organisms in testing. NIES contributes
to such discussions about the breeding and experimental methodologies
for laboratory organisms (algae, water fleas, fish, and quail, etc.) needed
for the international guidelines, implementation of experiments, and their
evaluation.
Thus, at the international level as well, risk assessments are being conducted
on ecosystems consisting of diverse species, based on their toxicity to
reference organisms. However, the impacts can vary greatly depending on
the combination of chemical and species. For this, we are developing techniques
to assess ecological risk that take into account different combinations
of chemicals and organisms.
Assessing Quantities of Exposure to Chemical
Substances
For risk assessments, it is important to assess both the amount taken
into the body (intake) and amount the body is exposed to externally (exposure).
It is possible to estimate exposure amounts from environmental concentrations
and other means. However, measurement techniques must be developed that
can detect small quantities, because some chemicals result in impacts
over long periods of time even from small quantities. NIES is developing
automatic continuous measurement equipment for atmospheric concentrations
of many chemical substances thought to have impacts on human health.
In addition, because the amount of exposure can vary greatly depending
on where a person is living, in order to accurately assess environmental
risk, it is essential to determine the amount of exposure based on both
time and location. For this purpose, NIES is developing a model to estimate
exposure, based on the temporal and spatial changes in the spread of chemicals
into the environment as well as environmental concentrations.
Comparison between
manual and automatic measurements of atmospheric concentrations
Using Organisms for Rapid
Environmental Risk Assessment
Analysis of chemical substances in the environment one-by-one would require
exorbitant costs. In addition, the combined effects of simultaneous exposure
to a range of chemicals are not well understood. NIES is developing bioassay
techniques (biological testing) to help determine environmental risks
in a comprehensive way, using organisms and cultured cells.
As a method of determining health effects, we are testing an approach
to risk assessments for chemicals in water, using cultured cells and microbes.
In addition, we are developing a method that uses fish to detect substances
that pose high mutagenic risks. We are also working to select, standardize
and simplify the most effective among existing bioassay techniques, in
order to make them easier to use. 
Toxicity testing using
cultured cells
Development of Methods to Manage Environmental
Risk
Because of the large number of chemical substances that must be dealt
with, the costs of risk management are rising year after year. NIES is
studying cost-effective risk management approaches based on risk assessments.
In order to conduct efficient risk management, it is essential to focus
on certain target substances. For this purpose, NIES is developing risk
assessments that can be done even based on limited available information.
In addition, we are developing an optimal system for the planning of
risk management that draws on information relating to exposure and the
movement of chemicals through the environment, such as information reported
through Pollutant Release and Transfer Register (PRTR) systems.
Risk management must inevitably be conducted even though uncertainties
remain. For this reason, it is important to develop consensus in society
about these issues. NIES is researching how to present information to
the public in ways that are easy to understand, in order to conduct risk
communication effectively.
In addition, we are developing techniques to promote risk communication,
using a participatory style of information provision.
NIES is developing
systems for risk assessment and risk management of substances that pose
environmental risks. Part of this work includes a geographic information
system (GIS) that integrates data into one model, including risk-causing
activities, emissions volumes, concentrations in various environmental
media, and the various levels of impact on humans and ecosystems.
