Controlling pesticide and other residues in herbs and spices 43
have tried to standardise permitted residue levels by product category. As the range
of herbal products continues to grow, this has become an increasingly difficult task.
At the same time, new cultivation techniques are evolving to increase productivity of
high-quality raw materials with a higher content of active ingredients, resulting in
increasing use of chemicals to boost yields and control pests. The high-yielding
hybrid varieties are often more susceptible to pest attack, and hence require greater
use of pesticides.
Regulations covering the use of pesticides are based on data generated by
environmental impact assessment (EIA) systems, which compare the characteristics
and effects of different pest control systems and generate an index or ranking of pest
control options. These types of assessment tools are also called pesticide risk indicators.
There are three categories of assessment system:
- Those that aid farmers/growers and other land managers.
- Research and policy tools for use by governments, industry or academia.
- Eco-labelling systems designed to influence consumer opinion and market
behaviour.
The methodologies employed by the EIA include simulation of environmental effects
(e.g. by computer modelling), sampling, monitoring and tracking changes in biophysical
indicators (such as species diversity, soil respiration rate, and chemical levels in the
environment), surveys and qualitative research methods, and indexing or ranking the
extent and severity of pesticide (both chemical and non-chemical pest controls)
impacts on one or more environmental indicators.
One of the primary objectives of assessing the environmental impacts of agriculture
is to choose those pest control practices that have the least negative impacts on the
environment, and on human health and safety. Policy makers then need to make
broad-brush appraisals of the impacts of such choices. Today, the challenge before
them is more complex as the number of chemical classes of pesticide has quintupled
from approximately 25 in the 1970s to about 130 in 1990s, and the modes of pesticide
activity affecting the environment have also diversified. In the USA, approval for the
use of pesticides is given by the U.S. Environmental Protection Agency (EPA). The
EPA is authorised by law to regulate the development, distribution, use and disposal
of pesticides. Before approving or registering a pesticide for use in agriculture, the
EPA normally requires close to 120 different tests – depending on the uses of the
pesticide – to determine its safety. The agency registers only those pesticides that
meet their standards for human health, the environment and wildlife. If new research
shows that any registered pesticide does not meet their standards, the EPA can cancel
or modify its use. While approving a pesticide, the EPA specifies instructions for its
use on the label, which must be followed by law. The agency also establishes a
tolerance (maximum residue level of a pesticide legally permitted in or on a food) for
each pesticide it approves. The tolerance ensures that, when pesticides are used
according to label directions, the residues will not pose an unacceptable health risk
to anyone, including infants, who consumes the food. Tolerances are considered an
enforcement tool and are used by the FDA in its monitoring program to ensure a safe
food supply. If any pesticide residue is found to exceed its tolerance on a food, then
the food is not permitted to be sold.
The Food Quality Protection Act, signed into law in 1996, sets an even tougher
standard for pesticide use in food. The EPA will consider the public’s overall exposure
to pesticides (through food, water and in home environments) when making decisions