Schaub 4:00
L03
ETHICAL CONFLICTS REGARDING CHEMICALS IN CERAMIC WATER
FILTERS
Nicole Cimabue (nec34@pitt.edu)
INTRODUCTION: THE INACCESSABILITY
OF CLEAN DRINKING WATER AND
ETHICAL CHALLENGE
Ceramic water filters are practical and inexpensive
purification systems that cleanse polluted water to make it
suitable for drinking purposes. These filters are designed for
third world environments lacking clean water which have
access to clay, water, sawdust and a chemical component, the
few materials needed to construct the filters. The water is
cleansed by filtering large particles from contaminated
sources through microscopic pores of a ceramic basin. Then
the water is further cleansed by sending it through a chemical
compound to exterminate toxic bacteria. The chemical
compound used in this method is extremely important to the
purification process and reduces a large proportion of bacteria
found in contaminated water sources. The chemical typically
used in purification is silver oxide (AgO), however other
chemicals such as copper (II) sulfate (CuSo4), trioxygen (O3)
and chlorine dioxide (ClO2) are equally effective at cleansing
water and may be substituted into the system [1]. While the
substitution of the chemical compound will produce the same
quality of purification, the cost and health risks posed by
different types of chemicals varies greatly. Typically,
chemicals of a higher concentration are more hazardous to the
health of consumers than silver oxide, which is why the latter
chemical is favored in water purification systems.
Ethical Conflict
The civil engineering company, Pure Water, provides a
team of engineers to design ceramic water filters and are
aware of the ability to substitute the chemical compound to
achieve the same level of purification. One engineer on the
team has proposed the idea of purchasing the chemical
chlorine dioxide (ClO2) instead of the original silver oxide
(AgO). The price of ClO2 is 4 times less than that of the AgO.
By changing the chemical component of the filters from AgO
to ClO2, the company will save $20,000 on this project. Many
engineers on the team agree that purchasing ClO2 will benefit
the company more than the alternative. However, while
chlorine dioxide has proven to be just as effective at purifying
water as silver oxide, it poses serious health hazards that could
be dangerous to the consumers who will use the ceramic water
filtration systems.
The health hazards that ClO2 poses to consumers are
mainly cancer-causing particles. While all chemicals in a
greater concentration pose a small risk to a consumer’s health,
University of Pittsburgh, Swanson School of Engineering 1
2013-10-29
the risk of ClO2 is much larger than alternative chemicals. In
addition to the health hazards, the purchase of this chemical
with the knowledge of dangerous health risks will break the
fundamental canons detailed in the engineering Code of
Ethics. The Code of Ethics referred to by the engineers of Pure
Water were created by the National Society of Professional
Engineers and the American Society of Civil Engineers.
The members of the team who were assigned this project
are made aware of the conflict between the cost and safety and
must determine whether they will use the less expensive
though hazardous chemical chlorine dioxide, or the original
chemical silver oxide, which poses minimal health hazards to
the consumer, but costs four times the price of ClO2. The
purchase of this chemical will save Pure Water $20,000 over
the period of one year, but will break rules stated in the Civil
Engineering Code of Ethics.
THE ROLE OF CHEMICAL PURIFICATION
IN CERAMIC WATER FILTRATION
Ceramic water filters use two methods to purify a
contaminated water source: filtration through a porous system
and chemical alteration. The porous method cleanses large
particles found in dirty water that are easily removed, while
the chemical method purifies microscopic bacteria that are
extremely hazardous and difficult to exterminate. Water that
is filtered through the pores of a ceramic water filter will have
contaminates such as dirt, rocks, and insects removed. The
cleansing of these larger particles from the water source aids
the purification process, however without chemical alteration
the pores do not cleanse the water enough for it to be
acceptable for consumption. Chemical alteration is a crucial
step in water filtration that removes lethal bacteria still
remaining in the source. Bacteria such as E. Coli and fecal
streptococci, both typically found in the water sources of
impoverished countries, can be cleansed this way [2].
The engineers of Pure Water considered eliminating the
chemical component of ceramic water filtration to decrease
the cost of the filter overall. Although removing the chemical
component would benefit the company financially, the overall
quality of the water source would not be acceptable for
drinking standards presented by the United States
Environmental Protection Agency (USEPA). The USEPA
states that a water source must contain “less than 1.0 mg/l of
a hazardous chemical” to be acceptable to drink [3].Without
chemical alteration, the water produced by the filter would
contain a sum of bacteria greater than 1.0 mg/l, rendering the
source inadequate for consumption.
Nicole Cimabue
FIGURE 1 [4]
Water molecules filter through a chemical compound
water the ceramic water filters produce, and to avoid breaking
Canon 1 of the NSPE Code of Ethics.
COMPARISON OF CHLORINE DIOXIDE
AND SILVER OXIDE
The engineers have decided against eliminating the
chemical compound that is crucial to the filtration system and
have instead decided to assess the differences between the two
chemicals chlorine dioxide and silver oxide. They decide to
compare the cost of purchasing each chemical, the ability of
the chemicals to purify water and the health hazards that affect
the safety of the water produced. By comparing these
characteristics of the different chemical components they will
obtain a greater knowledge of each chemical that will lead
them to make a well-informed decision while remaining in
accordance with the NSPE Code of Ethics.
The chemical compound exterminates harmful bacteria that
have not already been eliminated by the pores of the ceramic
filter. Then it removes most dissolved organic particles,
dissolved inorganic particles and bacteria. [5].
Comparison of Cost
The team considers the cost of each chemical per filtration
device. The average cost of producing one ceramic filtration
system ranges from $7.50 to $30 including the cost of the
chemical component [7]. For a filter that only needs to be
purchased one time, this system is a more affordable option
for most families living in developing countries. Both
chemicals AgO and ClO2 are less expensive in cost than other
purification options such as copper (II) sulfate, which costs
$50 per liter. The average price of one liter of silver oxide is
$32. Compared to the $5-$7 cost per liter of chlorine dioxide,
silver oxide is an average of $26 more expensive [8]. To
produce a mass quantity of ceramic filters, a large amount of
chemical compound must be purchased. Purchasing a year’s
supply of AgO would cost Pure Water $41,500, while ClO2
would only cost $21,500.
Regarding the Code of Ethics
The amount of bacteria which remain in chemically
untreated water not only exceeds the limit allowed by the
USEPA, but also encourages breaking rules in the Code of
Ethics created by the National Society of Professional
Engineers (NSPE). The NSPE Code of Ethics for Engineers
describes a variety of ethical canons which guide practicing
engineers. Under the Fundamental Canons, Canon 1 states,
“Engineers in the fulfillment of their professional duties shall
hold paramount the safety, health, and welfare of the public”
[6]. This canon displays the responsibility of Pure Water to
maintain a safe and healthy product that can be utilized by
consumers. By removing the chemical component of
filtration, the produced water is not suitable for consumption
and therefore endangers the safety and health of the
population in contact with the water.
All of the engineers on the team except for one decide it
would be a good idea to remove the chemical compound from
the system. The team looks to Section A under Canon 1 which
states, “If engineers’ judgment is overruled under
circumstances that endanger life or property, they shall notify
their employer or client and such other authority as may be
appropriate” [6]. The engineer opposed to removing the
chemical presents this information to the rest of the team. The
team realizes the potential for a hazardous situation to occur
and the possible notification of an authority figure to arise
with the removal of the chemical compound. The engineers
determine they will be conducting unethical actions if they do
not include the chemical in the system.
The engineers decide against the proposal to remove the
chemical component of filtration and decide to pursue other
options. This decision was made to maintain the quality of
Ethical Evaluation
Taking into consideration the significant price of silver
oxide, the engineers must weigh the costs with the
effectiveness and safety of each chemical. One engineer on
the team proposes the idea of altering the information that will
be presented to consumers in favor of chlorine dioxide. This
alteration will contain false information that may be
dangerous to the consumer of the product. Consulting the
American Society of Civil Engineering (ASCE) Code of
Ethics, the engineers find that Canon 3 states, “Engineers
shall issue public statements only in an objective and truthful
manner” [9]. Due to this rule, falsifying any facts that will
mislead the consumer for profit of the company is unethical.
The team decides against altering the public statement to
avoid unethical behavior.
The engineers also consult an article from the New York
Times regarding ethical engineering. The article discusses the
lack of information on specific subjects that could provide an
2
Nicole Cimabue
easy outlet to falsify facts. Dr. Fang, editor in chief of the
journal Infection and Immunity, described his experience
when searching for infection and immunity articles online,
“My search has only retracted nine articles over a 40-year
period” [10] This proves the lack of information available
about specific subjects which leaves room for interpretation
which can be ethically questionable. The engineers of Pure
Water have been unable to find much information regarding
the safety of chlorine dioxide and question whether they
should publish the fact that it is safe in favor of their filter.
Taking into consideration the ASCE Code of Ethics and
the New York Times article, the team decides that falsifying
any facts that will mislead the consumer for profit of the
company is unethical. They use their better judgment and
decides against altering the public statement to avoid
unethical behavior.
determine it is unethical to make specific conclusions based
on the fact that little information is provided. Since they
cannot come to an informed conclusion, they determine that
it would be unethical to exchange silver oxide for chlorine
dioxide without extensive information on the effectiveness of
chlorine consumption.
Comparison of Health Risks
The chemical silver oxide is a compound typically used to
purify contaminated water sources. Researchers for the World
Health Organization have studied the effects of silver
compounds in the purification of water by adding 1 gram of
silver to toxic metals. They then observed the health effects
the silver created on participants of the experiment. After no
change in the health of the participants, they concluded that
“silver to the contribution of drinking-water will normally be
negligible” [11]. The conclusions of the World Health
Organization prove that silver as a form of purification has no
extreme health effects on human health.
While ClO2 is less expensive than AgO and adequately
effective at purifying water, it poses health risks that are more
dangerous than those of AgO. Levels of ClO2 that exceed 1.0
mg/L are extremely dangerous to the health of consumers [3].
For example, when ClO2 exceeds 1.0 mg/L it increases the
likeliness of exposure to toxins present in the contaminated
water. When these toxins combine with a large concentration
of chlorine dioxide, they produce cancer-causing compounds
such as trihalomethane. [12]. These dangerous compounds
can lead to further health ailments that will endanger the lives
of consumers.
Comparison of Effectiveness
The chemicals silver oxide (Ag2O) and chlorine dioxide
(ClO2) are both labeled as “water purification chemicals” [1].
Both hold the potential to cleanse contaminated water, but not
necessarily the ability to purify it enough to be safe for
consumption. Scientists at the Nanyang Technological
University have tested the ability of silver compounds to
purify water by manufacturing silver crystals and recording
the amount of toxins they absorb in the given water supply.
They have determined “the Ag [silver] crystals have excellent
disinfection efficacies showing close to a 3 log reduction of
viable bacteria after a brief 15 s contact time” [9]. The 3 log
reduction of bacteria in the study displays a substantial
reduction in harmful particles that were present in the original
sample. The conclusions from the study prove that silver
compounds are adequate in purifying water supplies.
Considering chlorine dioxide, Pure Water engineers were
unable to find many articles on the subject. However
regarding chlorine toxicity in general, researchers at the
University of California have performed a study on the ability
of chlorine dioxide to disinfect noroviruses. Their study
concluded that the “adequate treatment of water with either
chlorine or ClO2 is likely to effectively control the waterborne
transmission of human norovirus” [10]. Since noroviruses are
typically found in the contaminated water sources of third
world countries, chlorine would be a beneficial chemical
component to use in a ceramic water filter. The knowledge
that ClO2 is an effective chemical compound supports the
argument of the engineers to use this chemical instead of
AgO.
Ethical Evaluation
Conflicted whether to use this chemical, the engineers
consulted an ethical case study involving the repercussions of
chemical contamination. In this case, engineers working for
the company Sanlu in China created a milk powder product
designed to be consumed by infants. Scientists discovered that
the powder was contaminated with a dangerous chemical,
melamine. The engineers knowingly contaminated this
product and endangered the health and safety of the
consumers who purchased the powder. They were held
responsible for their actions and were arrested by the Chinese
government [13]. Their knowledge of the contamination
displays unethical judgment because of their lack of
accordance with the NSPE Code of Ethics. The engineers
working for Sanlu did not create their product under the
guidance of Canon 1 of the Code of Ethics which takes into
consideration the safety of the consumer.
Pure Water engineers’ ethical dilemma is similar to that
of the Sanlu engineers. If Pure Water uses ClO2 in their filters
knowing the extreme health hazards that could harm their
consumers, they will also be breaking the first canon of the
NSPE’s Code of Ethics which is punishable by law. They will
Ethical Evaluation
The engineers at Pure Water decide that the effectiveness
of ClO2 to purify water is equal to that of AgO. However,
they were unable to find many sources on the topic of chlorine
compound effectiveness. Considering the New York Times
article regarding lack of online information, the engineers
3
Nicole Cimabue
endanger not only the lives of others but also forfeit their
credentials as professional engineers.
The Pure Water engineers are made aware of the health
risks posed by the use of ClO2 in their filters. By using this
harmful chemical to purify a contaminated water source they
will be breaking Canon 1 of the ASCE Code of Ethics
previously stated regarding safety, heath, and welfare of the
general public [14].
level of 1.0 mg/L would be exceeded, rendering the water
unsafe. The production of unsafe drinking water would be
harmful to consumers, making it unethical according to the
NSPE Code of Ethics. They eventually decided against
eliminating the chemical component and instead considered
the factors of cost, effectiveness and health risks.
When the engineers considered the alternative factors,
they concluded that while the cost of ClO2 would benefit their
company Pure Water, the chemical also possessed cancercausing capabilities that would endanger the consumer and
insubstantial evidence of effectiveness in comparison to AgO.
The engineers considered falsifying facts to keep the price of
the filters low while still producing them. After considering
the ASCE Code of Ethics, referencing articles in the New
York Times, and researching a case study regarding engineers
of Sanlu, they decided that making false claims and
endangering the safety of consumers would be unethical.
In conclusion, engineers at Pure Water have decided to
use the chemical silver oxide in the production of their
filtration systems to avoid unethical behaviors.
CONCLUSION
After assessing the cost benefits of using chlorine dioxide
to purify a contaminated water source and comparing them to
the effectiveness and health risks posed by the same chemical,
the civil engineers at Pure Water have decided to use the
original chemical, silver oxide, in the filtration process. Their
decision was based on ethical cases found through research
and consultation of the NSPE and ASCE Codes of Ethics.
The engineers first considered the need for a chemical
compound in the ceramic filtration system. They discovered
that without the chemical factor, a minimum contamination
4
Nicole Cimabue
REFERENCES
ACKNOWLEDGEMENTS
[1] Water Treatment Solutions. (2010). “Biocides.” Lenntech,
(Online blog). http://www.lenntech.com/biocides.htm
[2] A. Pickering. (2010). “Hands, Water and Health: Fecal
Contamination in Tanzanian Communities with Improved,
Non-Networked Water Supplies.” Environmental Science
and Technology. (Online article).
http://serialssolutions.com
[3] B. Cittadini. (2011). “Inorganic by-products in waters
disinfected with chlorine dioxide.” Microchemical Journal.
(Online Article.)
http://ac.els-cdn.com/S0026265X04002085/1-s2.0S0026265X04002085-main.pdf?_tid=677bcdb2-3f46-11e3aff000000aab0f27&acdnat=1382905916_3788210bdc1681978d
2b8b454c72e94c
[4] Filters Fast. (2013). “A Simple Guide to Water Filtration.
FiltersFast.
(Online
article).
http://www.filtersfast.com/articles/Guide-to-WaterPurification.php
[5] “How Does It Work.” (2013.) Potters for Peace. (Video)
http://www.cdc.gov/safewater/PDF/Ceramic_2011-final.pdf
[6] “Code of Ethics.” (2013). National Society for
Professional
Engineers.
(Online
article).
http://www.nspe.org/Ethics/CodeofEthics/index.html
[7] “The Safe Water System.” (2012). Centers for Disease and
Control Prevention. (Online article).
http://www.cdc.gov/safewater/ceramic-filtration.html
[8] Alibaba. (2012). “Nano Silver Solution.” (Online article).
http://www.alibaba.com/showroom/nano-silversolution.html
[9] “Code of Ethics.” (2013). American Society of Civil
Engineers.
(Online
article).
http://www.asce.org/Ethics/Code-of-Ethics/
[10] S. Loo. (2013). “Superabsorbent Cryogels Decorated
with Silver Nanoparticles as a Novel Water Technology for
Point-of-Use Disinfection.” Environment Science &
Technology.
(Online
article).
http://pubs.acs.org/doi/abs/10.1021/es401219s?source=cen
[11] M. Lim. (2010). “Disinfection kinetics of murine
norovirus using chlorine and chlorine dioxide.” Water
Treatment. (Online article).
http://www.sciencedirect.com/science/article/pii/S00431354
10001764
[12] World Health Organization. (2010). “Silver in Drinkingwater.” Guidelines for drinking-water quality. (Online
article).
http://www.who.int/water_sanitation_health/dwq/chemicals/
silver.pdf
[13] GaleGroup. (2011). “Silver Compounds.” (Online
article).
http://galegroup.com/
[14] BBC News. (2010). “Timeline: China milk scandal.”
(Online article).
http://news.bbc.co.uk/2/hi/7720404.stm
I would like to thank everyone at the Writing Center for
assisting me with the organization of this paper, my peer
engineering students with whom I discussed specifics of my
research with, and my Mom for proofreading this document.
5