LET’S CHECK
Activity No. 4. Now that you have known the most essential terms in the study
of environmental science. Let us try to check your understanding of these
terms. In the space provided, write the terms, being asked in the following
statements:
_____Health_______1. The state of complete physical, mental, and social
well-being, not merely the absence of disease or infirmity.
_____Disease______2. Refers to the impairment of an individual’s well-being
and ability to function often due to poor adjustments between the individual
and the environment.
_____Pollution______3. Refers to the unwanted change in the environment
caused by the introduction of harmful materials or the production of harmful
conditions.
_____Carcinogen____4. A toxin that increases the risks of cancer.
_____Allergens______5. Refers to substances that activate the immune
systems.
_Endocrine disruptors_6. It refers to chemicals that disrupt normal hormone
functions.
_____Mutagens______7. An agent which damage or alter genetic materials in
cells.
___Biomagnification___8. It occurs when toxic burden of a large number of
organisms at a lower trophic level is accumulated and concentrated by a
predator in a higher trophic level.
____Perchlorate______9. A waterborne contaminant left over from propellants
and rocket fuels.
______Synergism_____10. An interaction in which one substance
exacerbates the effects of another.
LET’S ANALYZE
Activity No. 4. Getting acquainted with the essential terms in studying
environmental toxicology and health, evolution, ecosystems, and interactions
will not be sufficient. What matters is that you should be able to identify and
discuss different toxic elements present in the environment, whether naturally
occurring or human-induced. It is also important to determine the route and
persistence of these pollutants to develop measures and mechanisms to
reduce the risk of potential food contamination and other agricultural resources.
Now, I will require you to explain your answers thoroughly.
1. What is biomagnification? Why is it essential in toxicology?
Biomagnification is a process that results in accumulation of toxins from
the base and concentration in the highest trophic level, which is caused by
organisms ingesting other organisms. Causes of biomagnification includes
products in agriculture, industrial activities, organic containment, and mining.
It’s notable significant effects on human health includes acquiring cancer from
what we thought were healthy foods such as seafoods, which occurs because
of the presence of mercury accumulated in oceans. Biomagnification is
essential in the field of toxicology because it provides crucial information to
raise awareness, prevent, or reduce the likelihood that its negative effects to
human and ecosystem would occur.
2. Differentiate acute effects from chronic effects.
Acute effects are caused by a single reaction to the toxin, and result in an
immediate health problem of some kind. It usually occurs promptly as a
product of short-term exposure and its duration is short. Additionally, its effects
are reversible thus, there is a possibility that a person survives an urgent crisis
due to acute reaction. However, if the effects have resulted or developed in
becoming permanent, then it is considered chronic. Chronic effects are usually
products of long-term exposure, and occurs over a longer period of time than
acute effect.
3. Identify and discuss comprehensively the components of risk management.
Risk management is composed of hazard identification, dose-response,
exposure assessment, and risk characterization. To start with, the objective of
hazard identification is to recognize the classification of adverse health effects
which can be caused by exposure to some agent in question. In addition to
that, it’s objective is to characterize the quality and weight of evidence
supporting this identification (EPA, 2017). It is the process of ascertaining
whether exposure to a stressor can create growth in the incidence of particular
adverse health effects. The second component is dose-response which
objective is to document the relationship between dose and toxic effect. It
explains how the probability and severity of adverse health effects (response)
are related to the extent and condition of exposure to the agent (the dose
provided).
On the other hand, exposure assessment’s objective is to calculate a
numerical estimate of exposure or dose. It measures or estimates the
magnitude, frequency, and duration of human exposure to an agent in the
environment, or estimating future exposures for an agent that has not yet been
released (EPA, 2017). Lastly, the objective of risk characterization is to identify
health risks in terms of the magnitude of the health issues and concerns that
might result from exposure to a particular pollutant or toxin.
4. How are toxic elements being deposited in the environment? Can these
toxic elements/ chemicals contaminate the food chain?
Toxic elements are deposited in the environment in different ways such as
anthropogenic activities (e.g. mining), industrial production and use,
agricultural and domestic activities, atmospheric deposition, and natural
phenomenon (e.g. weathering). Certainly these toxic elements can
contaminate the food chain by the process of biomagnification which is the
accumulation of unimportant and occasionally dangerous substances at
different levels of a food chain. When toxic wastes are deposited on the sea
bed, the bottom feeders of the food chain consume these dangerous wastes,
and it is slowly carried to the top of that specific food chain.
IN A NUTSHELL
Activity No. 4. Studying the environment and its components requires a deeper
understanding of the core areas of environmental science. This involves
understanding the influence of human dimensions as well as the natural
phenomena that resulted in different alterations of the natural ecosystems,
which eventually creates threats and danger both the biological, physical, and
chemical components of an ecosystem. Also, this includes the analysis and
understanding of how humanmade and natural components react with one
another. Based on the definitions and the essential elements in the study of
environmental and the learning exercises that you have done, please feel free
to indicate your arguments or lessons learned below.
1. Different types of elements, whether naturally present or human-induced,
have implications for biological safety as these elements tend to persist in the
environment due to its non-biodegradable nature. Since it continues, it poses
threats to human health as well as security and food safety.
2. The disease is considered an environmental response or an imbalance
within an ecosystem. This signifies that the carrying capacity of the
environment has been reached which makes a particular ecosystem unable to
function very well that resulted in the or reduce the ability to assimilate
pollutants and recover.
YOUR TURN
3. Toxicology plays an essential role in our society because it imparts crucial
information and knowledge which can be used to reduce or even prevent the
likelihood of getting diseases or fatalistic health problems. Moreover, it gives
awareness to us individuals to be more cautious of our actions and decisions.
4. We may be unaware but chemicals are all around us. Some things that we
incorporate in our daily lives are actually made up of harmful chemicals. Take
for example, endocrine-disrupting chemicals (EDCs) are present is detergents,
toiletries, cosmetics, plastic containers, food additives, solvents, pesticide,
prescription drugs, flame retardants, food packaging, inks and paints.
5. Pollutants are usually introduced into the environment through point sources,
area sources, and mobile sources. Point sources include factories and power
plants, while area sources include cities and agricultural areas, and mobile
sources include cars.
6. Neurotoxins are toxins that are damaging to nerve cells (neurons). It has
different types which acts in different ways. For example, organophosphates
such as parathion damages acetylcholinesterase, which is an enzyme in our
body that is crucial in controlling nerve signals in our body.
7. Atrazine which is a member of triazine chemical class and is usually used
for crops as herbicides, is also the cause of disruption and damage to the
hormonal functions in mammals of their endocrine system. Additionally, it is
the number one contaminant in ground drinking and rain water. Moreover,
human exposure to it is characterized with numerous serial health effects.
8. Soil is composed of layers called soil horizon. O horizon is the topmost layer
of the soil which is mostly comprised of decomposed organic materials such as
humus. A horizon which is found below O horizon is composed of both mineral
and organic matters. Below A horizon is horizon E which is composed of
light-colored materials. Next to horizon E is horizon B which is also known as
the zone of accumulation. Lastly, horizon C is composed of partially altered
(weathered) parent material.
9. Macronutrients and micronutrients are closely related terms that differ from
each other. Macronutrients are essential chemical elements that are
necessary for all living organisms in relatively large quantities, while
micronutrients are essential chemical elements that are only needed in small
quantities.
10. Pesticides are usually toxic chemicals that kill pests. Different types of
pesticides are used for different pests. Insecticide kills insects, herbicide kills
plants, rodenticides kill rodents, fungicides kill fungi, larvicides kill larvae,
bactericide kills bacteria, and biocide kills wide range of living things.