CHEMICAL SAFETY
Outline
Chemical Safety
a) Chemical risks to human health
b) Introduction to toxicology
c) Common groups that cause health risk
i.
ii.
iii.
iv.
v.
d)
Acids and bases
Dusts, fumes and gases
Metals
Pesticides
Solvents
Safety data sheet
Why worry about chemical safety?
Chemicals used everyday at home
and in the workplace can be
hazardous.
This Photo by Unknown Author is licensed under CC BY
Risks and Hazards
Approximately 1,000 new chemicals come onto the market every year, and about
100,000 chemical substances are used on a global scale.
Images from: https://www.sciencephoto.com/media/640762/view/domestic-chemical-products
https://www.knoell-swiss.com/en/business-units/industrial-chemicals-1
http://www.greenyield.com.my/agricultural-chemicals
Risks and Hazards
Hazard
Risk
• Potential of a substance to cause
damage
• Measure of the probability that harm
will occur under defined conditions of
exposure to a chemical
Risks are usually expressed as
probabilities
• Probability—a mathematical statement about the likelihood
that harm will be suffered from a hazard.
“The lifetime probability of
developing lung cancer from
smoking one pack of cigarettes per
day is 1 in 250.”
Risk assessment is the process of using statistical methods to
estimate how much harm a particular hazard can cause to human
can cause to human health or to the environment.
Risk management is the process of deciding whether or how to
reduce a particular risk to a certain degree.
We face many types of hazards
• Chemical hazards from harmful chemicals in air, water, soil, food,
and human-made products.
• Biological hazards from more than 1,400 pathogens that can infect
humans.
• Natural hazards such as fire, earthquakes, volcanic eruptions, floods,
and storms.
• Cultural hazards such as unsafe working conditions, unsafe
highways, criminal assault, and poverty.
• Lifestyle choices such as smoking, making poor food choices,
drinking too much alcohol, and having unsafe sex.
Chemists (and those exposed to
chemicals regularly) may have:
- Shorter lifespans, more disease
Hoar, S. K. et al, J. Occup. Med,. 23, 485 (1981)
- Higher cancer incidence
Dement J.M. & Cromer J.R., Appl. Ocup. Environ. Hyg., 7,120
(1992)
- Higher suicide rate (females)
Walrath J. et al, Amer. J. Pub. Health, 35, 883 (1985)
This Photo by Unknown Author is licensed under CC BY-NC-ND
organ
damage
weakening
of the
immune
system
cancer
Blindness
& death
Chemical
health
effects
effects on the
overall
development
of children
development
of allergies or
asthma
reproductive
problems and
birth defects
Chemical
risks to
human
health
Some toxic chemicals
Vinyl
chloride
Lead
Asbestos
Carbon
tetrachloride
Mercury
Thalidomide
Methanol
CO, CS2
Arsenic
Polychlorinated
biphenyls (PCBs)
etc
Some toxic chemicals
Vinyl
chloride
Lead
Asbestos
Carbon
tetrachloride
Mercury
Thalidomide
Methanol
CO, CS2
https://helix.northwestern.edu/article/thalidomidetragedy-lessons-drug-safety-and-regulation
Arsenic
Polychlorinated
biphenyls (PCBs)
etc
Types of Exposure
Air and
inhalation
Skin and eye
contact/
absorption
Food, water,
and
ingestion
Transfer
across the
placenta
Chemical risks to human health
• The health risks of chemicals depend on several factors,
including:
• the type of chemical
• the amount you're exposed to
• when and how long you are exposed
• how you're exposed (through food, water, air, products)
• your age and general state of health
• Higher risk groups include children, pregnant women, seniors, people with pre-
existing health conditions and Indigenous peoples.
Some chemicals can cause cancers, mutations, and
birth defects
• There are three major types of potentially toxic agents.
• Carcinogens are chemicals, types of radiation, or certain
viruses that can cause or promote cancer.
• Mutagens are chemicals or forms of radiation that cause
mutations, or changes, in the DNA molecules found in cells,
or that increase the frequency of such changes.
• Teratogens are chemicals that cause harm or birth defects to
a fetus or embryo.
Some chemicals may affect our
immune system
• Our body’s immune system protects us against disease and
harmful substances by forming antibodies that render invading
agents harmless, but some chemicals interfere with this process.
• Arsenic - DNA damage in immune cells
• Methylmercury – effects on inflammatory pathways; dermatitis
• Dioxins – immunosuppression
Some chemicals may affect our
nervous system
• Some natural and synthetic chemicals in the environment, called
neurotoxins, can harm the human nervous system, causing the
following effects.
• Behavioral changes.
• Learning disabilities.
• Retardation.
• Attention deficit disorder.
• Paralysis.
• Death.
Some chemicals may affect our immune
and nervous systems
• Examples of neurotoxins.
• Polychlorinated biphenyls (PCBs)
• Methylmercury
• Arsenic
• Lead
• Certain pesticides
Polychlorinated Biphenyls (PCBs)
tasteless and odorless
https://web.uri.edu/lohmannlab/welcome/great-lakes-passive-sampling/data/pcbs/
https://www.spokaneaquifer.org/what-are-pcbs/
PCBs and other persistent toxic chemicals
can move via many pathways
PCBs, due to its toxicity, have been banned for a long time in the US, but
it's only been banned in the Philippines in 2004.
Arsenic contamination
• Industry
• Glass
• Pigments
• Textile
• Paper
• Metal adhesive
• Wood preservative
• Ammunition
• Agriculture
• Pesticides
• Animal feeds
• Groundwater
Arsenic contamination
https://www.theguardian.com/usnews/2020/jun/24/whole-foods-bottled-waterarsenic-found
Limit test for Arsenic
using lead acetate
Long-term effect of bushfires on water
quality
https://www.ecu.edu.au/news/latest-news/2020/06/drinking-water-under-threat-from-bushfire
https://www.news-medical.net/news/20200701/Bushfire-can-have-long-term-effects-on-water-quality.aspx
Lead contamination
Short-term overexposure
Long-term effects
Abdominal pain
Constipation
Irritability
Headache
Depression
Tiredness
Gets easily distracted
Loss of appetite
Forgetfulness
Memory loss
Pain or tingling in the extremities
Weakness
Exposure leads to higher risk for high blood pressure, heart disease, kidney
disease, and reduced fertility.
Nausea
Mercury in fish in the Philippines
The Centre for Food Safety (CFS) of the
Food and Environmental Hygiene
Department in Hong Kong announced
today (December 19, 2019) that a
sample of chilled swordfish imported
from the Philippines was found to
contain a metal contaminant,
methylmercury, at a level exceeding
the legal limit. The CFS is following up
on the case.
https://www.info.gov.hk/gia/general/201912/19/P2019121900557.htm
Mercury in fish in the Philippines
Low levels of mercury: These are the safest fish
and you may eat up to two to three servings per
week. Each serving weighs 180 grams or six
ounces.
Moderate levels of mercury: Limit eating to
one to two times (or servings) per week. Each
serving weighs 180 grams or 6 ounces.
1. Samaral
2. Dilis (anchovies)
3. Hito (catfish)
4. Galunggong (mackerel)
5. Salmon
6. Sardines
7. Tilapia
8. Low in mercury are shrimp, squid, and crab.
9. Bangus (milkfish) are safe but their mercury
levels are a bit higher than the rest in this group.
High levels of mercury: At most, you should
only eat three times (or three servings) in a
month.
1. Banak (mullet)
2. Tamban
3. Maya-maya (snapper)
4. Canned light tuna
1. Tuna fresh or sashimi
2. Lapu-lapu (grouper)
3. Sea bass
https://www.philstar.com/lifestyle/health-and-family/2016/09/13/1623033/guidelines-eating-fish-safely
Methylmercury
• The EPA estimates that about 1 in 12 women of childbearing
age in the US has enough mercury in her blood to harm a
developing fetus.
• The greatest risk from exposure to low levels of methylmercury
is brain damage in fetuses and young children.
• Methylmercury may also harm the heart, kidneys, and immune
system of adults.
• EPA advised nursing mothers, pregnant women, and women
who may become pregnant not to eat shark, swordfish, king
mackerel, or tilefish and to limit their consumption of
albacore tuna.
https://www.youtube.com/watch?v=y8kEM-RKaek
Some chemicals may affect our immune and
nervous systems
• The main industrial sources of atmospheric mercury are mining,
coal burning, and other industrial activities
• About 50 tons of elemental mercury are emitted each year
from U.S. coal-burning powerplants, with lesser amounts
coming from oil- and gas-burning units.
• Recommendations to reduce mining and coal-burning, reduce
or eliminate mercury in the production of batteries, paints, and
chlorine.
at least 18 sites across the country, including
landfills and mining sites, as areas suspected
to be contaminated by the toxic metal
https://newsinfo.inquirer.net/1098667/mercury-level-rising-in-philippine-waters-mine-sites-18-hot-spots-tagged#ixzz6RDCrJA8a
Some chemicals affect the human
endocrine system
• The endocrine system is a complex network of glands that release tiny
amounts of hormones that regulate human:
• Reproduction.
• Growth.
• Development.
• Learning ability.
• Behavior.
Some chemicals affect the human
endocrine system
• Hormonally active agents (HAA) are synthetic chemicals
that disrupt the endocrine system in humans and some
other animals.
• HAA Examples include aluminum, Atrazine™ and several
other herbicides, DDT, PCBs, mercury , phthalates, and
bisphenol A (BPA).
• Some disrupt the endocrine system by attaching to
estrogen receptor molecules.
• Thyroid disrupters cause growth, weight, brain, and
behavioral disorders.
Some chemicals affect the human
endocrine system
• BPA is found in plastic water
bottles, baby bottles and the
plastic resins line food
containers.
• Studies found that low levels of BPA
cause numerous problems such as
brain damage, early puberty,
prostate cancer, breast cancer,
and heart disease.
Some chemicals affect the human
endocrine system
• Studies funded by the chemical industry found no evidence or only weak
evidence, for adverse effects from low-level exposure to BPA in test
animals.
• In 2008, the FDA concluded that BPA in food and drink containers does
not pose a health hazard.
• In 2010, Canada classified BPA as a toxic chemical and banned its use in
baby bottles, and the EU voted to ban the sale of plastic baby bottles that
contain BPA.
BPA alternatives
• BPA alternatives (BPS, BPF,
BPAF, BPZ, BPP, BHPF, etc.)
also negatively impacts
reproduction (Washington
State University)
https://earthhero.com/what-are-phthalates/
Some chemicals affect the human
endocrine system
• Phthalates cause cancer and
reproductive problems in laboratory
animals.
Toxicology
https://www.youtube.com/watch?v=A0NNyjVvnYo
Toxicology
The study of the harmful effects of
chemicals on humans and other
organisms.
• Toxicity is a measure of the
harmfulness of a substance.
• Any synthetic or natural chemical
can be harmful if ingested in a
large enough quantity.
All substances are poisons;
there is none that is not a poison.
The right dose
differentiates a poison from a remedy.
Paracelsus (1493–1541)
Toxicology
• The dose is the amount of a chemical
that a person has ingested, inhaled, or
absorbed through the skin.
• Many variables can affect the level of
harm caused by a chemical.
• Toxic chemicals usually have a greater effect
on fetuses, infants, and children than on
adults.
Scientists use live laboratory animals and
non-animal tests to estimate toxicity
In vivo testing: The most widely used method for determining
toxicity is to expose a population of live laboratory animals to
measured doses of a specific substance under controlled
conditions.
Dose-response curve
• Results plotted in a dose-response
curve.
• Median lethal dose (LD50) is the dose
that can kill 50% of the animals
(usually rats and mice) in a test
population within an 18-day period.
Toxicity ratings and average lethal doses
for humans
POTENTIALLY
HARMFUL
CHEMICALS
FOUND IN
MANY HOMES
Many factors determine the harmful
health effects of chemicals
• Toxicity also depends on genetic makeup,
which determines an individual’s sensitivity
to a particular toxin.
• Some individuals are sensitive to a
number of toxins—a condition known as
multiple chemical sensitivity (MCS).
• How well the body’s detoxification
systems (such as the liver, lungs, and
kidneys) work.
Many factors determine the harmful health
effects of chemicals
• Solubility: water-soluble toxins and oil- or fat-soluble toxins.
• Persistence, or resistance to breakdown such as DDT and PCBs.
• Biological magnification, in which the concentrations of some potential
toxins in the environment increase as they pass through the successive
trophic levels of food chains and webs.
Many factors determine the harmful health
effects of chemicals
• The damage to health resulting from exposure to a chemical is
called the response.
• Acute effect is an immediate or rapid harmful reaction
ranging from dizziness and nausea to death.
• Chronic effect is a permanent or long-lasting consequence
(kidney or liver damage, for example) of exposure to a single
dose or to repeated lower doses of a harmful substance.
There are other ways to estimate the harmful
effects of chemicals
Case reports provide information about
people suffering some adverse health
effect or death after exposure to a
chemical.
This Photo by Unknown Author is licensed under CC BY
Epidemiological studies, which compare
the health of people exposed to a
particular chemical (the experimental
group) with the health of a similar group
of people not exposed to the agent (the
control group).
Limitations of using case reports and
epidemiological studies
Too few people have
been exposed to
high enough levels
of a toxic agent
Takes a long time
Different sensitivity
to chemicals
People are exposed
to many different
toxic agents
New technologies or
chemicals
Are trace levels of toxic
chemicals harmful?
Trace level: substance is present in
very small amounts (<0.01%)
Everyone is exposed to potentially
harmful chemicals
Not much data is available for study
This Photo by Unknown Author is licensed under CC BY-ND
Why do we know so little about
the harmful effects of chemicals?
• Only 10% of 80,000+ registered synthetic
This Photo by Unknown Author is licensed under CC BY-SA
chemicals in commercial use have been
thoroughly screened for toxicity, and only 2%
have been adequately tested to determine
whether they are carcinogens, mutagens, or
teratogens.
• The use of ~99.5% of commercially available
chemicals are not supervised.
• All methods for estimating toxicity levels and risks
have serious limitations.
This Photo by Unknown Author is licensed under CC BY-ND
The use of data mining and AI for toxicology
This Photo by Unknown Author is licensed under CC BY-ND
Two big ideas
• Because of the difficulty in evaluating the harm caused by exposure to
chemicals, many health scientists call for much greater emphasis on
pollution prevention.
• Becoming informed, thinking critically about risks, and making careful
choices can reduce the major risks we face.
How far should we go in using pollution
prevention and the Precautionary Principle?
Pollution prevention: Do not release into the
environment chemicals that we know or suspect can
cause significant harm.
• Look for harmless or less harmful substitutes for toxic and
hazardous chemicals.
• Recycle them within production processes to keep them from
reaching the environment.
How far should we go in using pollution
prevention and the Precautionary Principle?
Precautionary principle: when there is reasonable but
incomplete scientific evidence of significant or irreversible
harm to humans or the environment from a proposed or existing
chemical or technology, we should take action to prevent or
reduce the risk instead of waiting for more conclusive scientific
evidence.
• New chemicals/technologies would be assumed to be harmful
until scientific studies could show otherwise.
• Existing chemicals/technologies that appear to have a strong
chance of causing significant harm would be removed from the
market until their safety could be established.
How far should we go in using pollution
prevention and the Precautionary Principle?
In 2007, the European Union enacted regulations known as
REACH (for registration, evaluation, and authorization of
chemicals) that put more of the burden on industry to show that
chemicals are safe.
• REACH requires the registration of 30,000 untested, unregulated, and
potentially harmful chemicals.
• The most hazardous substances are not approved for use if safer
alternatives exist.
• When there is no alternative, producers must present a research plan
aimed at finding one
Persistent Organic Pollutants (POPs)
• The “dirty dozen”: aldrin, chlordane, DDT, dieldrin, dioxins,
endrin, furans, heptachlor, hexachlorobenzene, mirex, PCBs,
and toxaphene
Common groups that cause health risk
Acids and
bases
Solvents
Dusts,
fumes and
gases
Pesticides
Metals
Acids and bases in the household
This Photo by Unknown Author is licensed under CC BY-NC-ND
This Photo by Unknown Author is licensed under CC BY-NC-ND
This Photo by Unknown Author is licensed under CC BY-NC-ND
This Photo by Unknown Author is licensed under CC BY-SA
This Photo by Unknown Author is licensed under CC BY
Acidic and Basic Properties
Acids
Property
Bases
pH level is less
than 7
pH level
pH level is greater
than 7
Sour in taste
Taste/feel
Bitter in taste, has
slippery or soapy
feel
Turns blue litmus
indicator to red
Litmus indicator
Turns red litmus
indicator to blue
Donates H+ ions
H+ ions
Accepts H+ ions
What makes acids and bases dangerous?
This Photo by Unknown Author is licensed under CC BY-SA
This Photo by Unknown Author is licensed under CC BY-NC-ND
Some acids and bases are corrosive
• Corrosive refers to a substance that has
the power to cause irreversible damage or
destroy another substance by contact.
• Strong acids and bases, especially if
concentrated, are corrosive
Severity of harm from acids and bases
• Depends on the following:
• Concentration of chemical
• Duration of exposure
• Routes of exposure
• Skin/eye absorption: Mixing strong acids and bases or adding water to
them produces heat
• AWA (Acid to WAter)
• Ingestion
• Inhalation: Mists of concentrated acids and bases can be breathed in
and attack the nose and lungs
Use of acids
• Some acids are explosive in contact with organic material like sawdust or
produce release flammable hydrogen gas in contact with metals
Strength of acids and bases
• The strength or weakness of acids and bases is determined by how they
ionize in solution.
Strong acids/bases: HCl → H+ + ClWeak acids/bases: HCN ↔ H+ + CN• However, there are some strong acids that are not corrosive such as
Carborane acids.
• There are some weak acids/bases that are highly corrosive such as
Hydrofluoric acid.
Health Hazard 1: Chemical Burns
• Description:
• Tissue damage caused by exposure to a strong acid
or alkali.
• Chemical Burn Levels
• A first-degree or superficial burn: affects only the
epidermis, minor discoloration of the skin
• A second-degree or partial thickness burn: affects
the epidermis and dermis. These burns can be very
red, inflamed, and painful, and can blister.
• A third-degree or full thickness burn: can cause
extensive damage to the epidermis and dermis, as
well as bones, tendons, muscles
Image ID :42756285
Media Type :Vector Illustration
Copyright :Luciano Cosmo
Health Hazard 1: Chemical Burns
• Route of Exposure:
• Contact with skin/eyes
• Common causes:
• Car battery acid - sulfuric acid (H2SO4)
• Bleach -Sodium hypochlorite (NaOCl)
• Ammonia - NH3
• Pool chlorination products – Hypochlorous acid (HClO)
• Liquid lye - Sodium hydroxide (NaOH)
• First Aid Procedure:
• Remove any contaminated clothing.
• Flush the affected tissue with water for at least 20
minutes
• Go to the hospital for injury assessment
Caution
•
Some graphic pictures are included in the case examples
presented
Case Report: Loss of Sight Caused by Calcium
Hydroxide Paste Accidentally Splashed into the Eye
during Endodontic Treatment
A dentist lost her eyesight when she accidentally splashed
calcium hydroxide into her own eye while applying an
aseptic endodontic treatment
The dentist underwent medical treatment after 30 minutes
of the incident. Medical report showed lack of tear
secretion, burned tissue, and other eye tissue damage.
Two days after the incident, her left eye was completely
healed (tissues) but due to severe damage, she lost all sight
in the affected eye.
Source: Lipzki, M., Radlinska, J., Gora, M.(2012, May 17). Loss of Sight Caused by Calcium Hydroxide Paste Accidentally Splashed into the Eye during
Endodontic Treatment: Case Study. Retrieved from http://www.jcda.ca/article/c57.
Health Hazard 2: Corrosive Poisoning
• Description: Poisoning with strong acids or alkalis
capable of causing rapid tissue destruction and
shrinkage.
• Common causes:
• Metal/toilet bowl cleaner - Hydrochloric acid
(HCl)
• Car battery acid - sulfuric acid (H2SO4)
• Paint remover/drain cleaner -Sodium hydroxide
(NaOH)
• Metal cleaners (nitric acid)
• Rust removers (hydrogen fluoride)
Case Report: Acute Formic Acid Poisoning
In A Rubber Plantation Worker
A patient consumed approximately 20ml of 85%
concentrated formic acid.
By 1st day, patient had complications such as
hematemesis, hematuria, and hemoglobinuria.
On the 2nd day, patient did not have any
hematemesis, her hematuria improved and her
coagulation profile was normal.
On the 3rd day, her liver enzymes and bilirubin levels
started improving.
On day 4, multiple ulcers were noted in her mouth
and throat. Patient was comfortable on day 4 and
throat pain had reduced.
Source: More, D., Vora, M., & Wills, V. (2014). Acute formic acid poisoning in a rubber plantation worker. Indian Journal of Occupational and Environmental
Medicine, 18(1), 29. doi:10.4103/0019-5278.134957
Case Report: Autopsy results of a case of
ingestion of Sodium hydroxide solution
A man in his 80s was found dead with a
mug and a bottle of caustic soda.
The man experienced liquefaction and
disappearance of his esophagus, trachea,
lung tissue and grayish discoloration of
the mucosa of the stomach.
The man’s gastrointestinal tract had a pH
level of 7-8. The man died shortly.
Source: Nagasaki, Y., Emoto, Y., Yoshizawa, K., Shikata, N., & Tsubura, A. (2015). Autopsy results of a case of ingestion of sodium hydroxide solution. Autopsy
Results of a Case of Ingestion of Sodium Hydroxide
Health Hazard 3: Acute Inhalation Injury
• Description:
• Injury in pulmonary epithelium at
various levels of respiratory tract,
leading from simple symptoms to
severe disease due to short-term
exposures to toxic substances on
the lungs.
• Route of Exposure:
• Inhalation
Case report: Accidental fatal inhalation of
sulfuric acid fumes
A man found dead, indicating exposure to sulfuric
acid vapor, while using a solution of concentrated
sulfuric acid to a drain pipe in an attempt to clear
a blockage.
Moderate corrosive damage around his mouth and
nose, on his forearms and tips of fingers of his left
hand.
Autopsy revealed congestion of the respiratory
passages. Traces of acid and sulfate compounds
were chemically detected in his upper respiratory
passages.
Source: https://www.sciencedirect.com/science/article/abs/pii/S1353113106001957
Case Report: Acute Lung Injury Following
Exposure To Nitric Acid
A 30-year-old man experienced
severe dyspnea, that caused him to
develop hypoxia after being
exposed to nitric acid fumes while
cleaning a nitric acid container in
the chemical and fertilizer unit
where he was employed.
None of the employees was wearing
any protective devices when the
incident happened.
Source: Jayalakshmi, T., Shah, S., Mehta, A. (2009, October). Acute lung injury following exposure to nitric acid. Retrieved from
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2876705/#!po=6.25000
CHEMICAL
IRRITANTS
CAUSING ACUTE
INHALATION
INJURY: THEIR
EFFECTS AND
SOURCES OF
EXPOSURE
Source: https://www.ncbi.nlm.nih.gov/pmc/articles/pmc4261306/
Dusts, fumes, and gases
Dust
• A common air pollutant generated by
many different sources and activities
such as grinding, milling, sanding, etc.
• Common in urban areas
• The natural erosion of soil, sand and rock
is the most common source of dust
Jan
2020
Apr
2020
Images from: https://news.abs-cbn.com/ and https://news.mongabay.com/
Dust Hazards
The effect depends on particle
size, amount, and nature
• particles < 10 µm in diameter can
be breathed deep in the lungs
• those < 2.5 µm may be
particularly dangerous, travels
faster and farther
Health Hazards
• Irritation of the eyes
• Coughing
• Sneezing
• Hayfever (rhinitis)
• Asthma attacks
Health Hazard 1: Eye irritation,
dry eye syndrome
• Dry eye syndrome may lead to itchiness
and dry, sand-like feeling in the eyes.
• May affect the tear glands, so it doesn’t
function properly as a lubricant to protect
the eyes.
• Route of exposure: eyes
• First aid/treatment procedure:
Artificial tears
http://www.koreatimes.com/article/20190325/1238479
Health Hazard 2: Coughing, sneezing,
and/or asthma attacks
Case report: Fine dust now a ‘disaster’ in
Korea
According to the ministry, multiple revision bills to the
Disaster and Safety Management Law, proposed to
include fine dust, are pending at the National Assembly.
The fine dust level reached 145 micrograms per cubic
meter Tuesday afternoon in Seoul. The World Health
Organization states anything over 25 micrograms is a
health hazard.
Among asthma patients, hospital visits went up by 0.23
percent in all age groups.
http://m.koreatimes.co.kr/pages/article.asp?newsIdx=262089
https://www.koreatimes.co.kr/www/nation/2019/03/356_265273.html
Health Hazard 3: Silicosis
Dusts containing crystalline silica or asbestos may cause silicosis
or incurable lung damage leading to cancer
Route of exposure:
inhalation
Silicosis, A Monumental Occupational Health
Crisis In Rajasthan - An Epidemiological
Survey
Silicosis has emerged at epidemic level in
Rajasthan due to exponential growth in the
mining sector.
One community has 77% positive cases for
silicosis
http://granthaalayah.com/Articles/Vol5Iss7/54_IJRG17_A07_558.pdf
Gas
• One of the fundamental states of
matter that has no fixed shape or
volume. It can be made up of
elemental or compound molecules
Gas Health Hazards and
Routes of Exposure
• Hazards
• Fire
• Routes of Exposure
• Inhalation
• Explosion
• Ingestion
• Eye irritation
• Direct contact
• Vomiting
• Cancer
• Organ damage
• Body system damage
Gas Toxins
Toxins
Effects
Ammonia
Mucous membrane irritation and sloughing
Bronchiectasis, pulmonary interstitial fibrosis
Ammonia, phosgene, hydrogen sulfide
Laryngeal edema and obstruction
Carbon monoxide, cyanide, hydrogen sulfide
Asphyxiation
Chlorine, phosgene
Acute respiratory distress syndrome
Hydrofluoric acid
Systemic effects, hypocalcemia, hypomagnesemia
Hydrogen chloride, chlorine
Tracheobronchitis
Hydrogen fluoride, mustard gas
Chemical pneumonitis
Hydrogen sulfide
Bacterial pneumonia
Nitric oxide
Systemic effects, methemoglobinemia
Oxides of nitrogen, sulfur oxides
Obliterative bronchiolitis (bronchiolitis obliterans)
Sulfur dioxide, hydrogen chloride, oxides of
nitrogen, ozone
Bronchoconstriction, airway edema, asthma
Case Report: Sarin gas exposure in Syria
• This is a man-made chemical warfare
agent that is toxic even at < 1 ppm
• Clear, colorless and odorless liquid but
can turn into gas
• Mitigation measures
• Leave the area where sarin was
released and get fresh air quickly
• If outdoors, go to the highest ground
possible
• If indoors, get out of the building
quickly
• When exposed, remove clothing,
rapidly wash body, get medical care
Case Report: Phosgene gas during WW1
• Phosgene is formed when solvents
containing chlorine come into contact
with hot surfaces or flames
• Phosgene can kill before its smell is
detectable (e.g. WWI)
• Can be produced in cigarettes in the
presence of chlorinated solvents in the
surrounding atmosphere
Carbon Monoxide
• Carbon monoxide is an odorless,
colorless gas formed by
incomplete burning of carbon
compounds
• It can gradually block oxygen
supply to the nervous system,
making your brain function less
effectively before it causes death
• It can bind with hemoglobin,
stopping it from carrying oxygen
in the blood
Hydrogen Cyanide
• Hydrogen cyanide gas can pass
through the skin, as well as the
lungs, and kills by depriving
your brain and heart of oxygen.
• It can block cell respiration
Fumes
• Vapors (gases), dusts and/or smoke
given off by a substance as a result
of a chemical transformation such
as reaction, heating, explosion or
detonation
Fumes Health Hazards and
Routes of Exposure
Short-term
Long-term
Irritation of the eyes, nose, and
chest
Chronic lung problems
Coughing
Cancer of the Larynx
Shortness of breath
Parkinson’s Disease
Bronchitis
Skin Diseases
Fluid in the lungs (Edema)
Hearing Loss
Inflammation of the lungs
Gastritis, ulcers of the stomach
Loss of appetite
Kidney damage
Cramps
Infertility
Nausea / Vomiting
Heart disease
• Routes of Exposure
• Inhalation
• Ingestion
Case study: Taal volcano eruption
• January 2020, Taal Volcano spewed steam, ash,
and small rocks.
• Volcanic gases, including sulfur dioxide, which
irritates the nose, throat, and airways to cause
coughing, wheezing, shortness of breath
• Fine ashfall can cause irritation and breathing
problems especially among the elderly and
children
• Ashfall have also experienced sulfurous smell
which can also cause irritation
Mitigation and treatment for fume
exposure
• Mitigation
• Improving ventilation
• Use of PPE (mask/respirator, eyewear,
protective clothing)
• Treatment
• Remove from source of exposure
• Treat chemical burns if present
• Monitor for responsiveness and breathing.
All suspected inhalation injuries require
medical attention
Heavy Metals
• Metallic elements that have
relatively high density
• Highly toxic
• Abundant in Earth’s crust
• Some are essential in certain
biochemical and physiological
processes in the human body
• Lethal to humans
Arsenic
• Can be acquired through ingestion of contaminated
food, inhalation, and dermal contact
Health Risk:
•
•
•
•
•
carcinogenic
causes developmental anomalies
diabetes
hearing loss
hematologic disorders
Mercury
• Most toxic heavy metal in the environment
Health Risks:
•
•
•
•
•
mainly targets the brain
neurotoxic
vapors can cause asthma
bronchitis
other temporary respiratory illnesses
Lead
• Most common water contaminant
• Exposure occurs via inhalation and ingestion
Health Risks:
•
•
•
•
targets nervous system
causes irritability
headache
loss of memory
Cadmium
• Widely distributed in the Earth’s crust, particularly
in sedimentary rocks
• Use in the production of alloys, pigments, and
batteries; also a component of cigarettes
• Exposure occurs when inhaled, ingested and when
smoked
Health Risks:
•
•
•
•
pulmonary and gastrointestinal irritant
pulmonary adenocarcinoma
acute ingestion will cause vomiting
abdominal pain and convulsion
Chromium
• Naturally present in the Earth’s crust
• Used in metal processing, stainless steel
welding and chrome pigment production
• Exposure occurs via inhalation and ingestion
Health Risk:
• targets the lungs
• causes dermatitis
• nose ulcers
• asthma
• cancer of respiratory tract
Case report: Dimethylmercury poisoning
in Dartmouth
• Karen Wetterhahn, professor and founding director of Dartmouth's
Toxic Metals Research Program
• expert in the mechanisms of metal toxicity
• In 1996, spilled a few drops of dimethylmercury on her gloved hand
• Cleaned up spill immediately
• Latex glove believed protective
• Six months later, became ill and
died of acute mercury poisoning
at age 48
…all rice varieties and fish samples showed the presence of lead. Only regular Malagkit and
NFA rice went above while all kinds and parts of fish went beyond the allowable limit for
lead in food.
Pesticides
• Chemical compounds that are used to
kill pests, including insects, rodents, fungi
and unwanted plants (weeds).
• Used in public health to kill vectors of
disease, such as mosquitoes.
• By their nature, pesticides are potentially
toxic to other organisms, including
humans
• Made up of active and inert ingredients,
mainly designed to be a poison
This Photo by Unknown Author is licensed under CC BY-NC-ND
https://panap.net/2016/10/vicious-cycle-pesticides/
PESTICIDE
TREADMILL
http://www.panna.org/gmos-pesticides-profit/pesticide-treadmill
Organophosphates (OP)
• Main components of herbicides,
pesticides, and insecticides, several of
which are highly toxic.
• Main components of nerve gas (e.g.
sarin).
• Targets neurotransmitters
• Worldwide, approximately 3 million
people are exposed to OPs with about
300,000 mortalities.
Dichlorodiphenyltrichloroethane (DDTs)
• The first synthetic, well-known, insecticide.
• Metabolized into dichlorodiphenyldichloroethene
(DDE) in the body.
• Both DDT and DDE can be stored in the body’s
fatty tissues
DDT
DDE
2,4-dichlorophenoxyacetic acid (2,4-D)
• One of the cheapest and most common
herbicide/weed killers in the US.
• Absorbed through the leaves, causing
uncontrolled, unsustainable growth.
• Stem curl-over, leaf withering, and
eventual plant death.
• Rapidly excreted from the body, primarily
in the urine.
http://mtvernon.wsu.edu/path_team/DiseaseGallery/
potato-2-4-d-drift-2.htm
Target: Plants
Herbicide alachlor, metalochlor, atrazine
Target: Parasitic Fungi
Captan, sulfur, mancozeb
Fungicide
https://www.dreamstime.com/illustration/spraying-insecticide.html
https://www.canstockphoto.com/illustration/fungicide.html
https://www.better-lawn-care.com/vinegar-weed-killer.html#sthash.r4ZHVKxg.dpbs
Types of
Pesticides
Target: Insects
Malathion, carbaryl, diazinon,
chlorpyrifos
Insecticide
Routes of Exposure and LD50
Routes of Exposure
• Inhalation in sufficient amounts may cause absorption through the
lungs into the bloodstream.
• The hazard of poisoning from respiratory exposure is great because
of the rapid and complete absorption of pesticides through lung
tissues
Health Hazards: Poisoning (Acute)
Mild
headache, fatigue,
weakness, dizziness,
restlessness, nervousness,
perspiration, nausea,
diarrhea, loss of appetite,
loss of weight, thirst,
moodiness, soreness in
joints, skin irritation, eye
irritation, irritation of the
nose and throat
Moderate
nausea, diarrhea, stomach
cramps, excessive
perspiration, trembling, no
muscle coordination,
muscle twitches, extreme
weakness, mental
confusion, blurred vision,
difficulty in breathing,
cough, rapid pulse, flushed
or yellow
Severe
fever, intense thirst,
increased rate of
breathing, vomiting,
uncontrollable muscle
twitches, pinpoint
pupils, convulsions,
inability to breathe,
unconsciousness
Health Hazards: Chronic Effects
• Endocrine disruptors interfere with
important bodily functions by mimicking
or blocking hormones.
• Cancer: brain cancer, breast cancer,
prostate cancer
• Respiratory complication: chronic
bronchitis, asthma, cough, suffocation
• Reproductive system: infertility, birth
defects, spontaneous abortion, sterility
• Neurotoxic: Parkinson’s disease, brain
cancer
https://english.madhyamam.com/en/editorial/2016/jan/28/painfultales-misery
Mitigation measures
Wear correct protective equipment
Follow safety measures
Use safer alternatives
Case Report: School groundskeeper dies
of cancer from pesticide
• A California man diagnosed with
non-Hodgkin's lymphoma, a cancer
that affects white blood cells, sued
Monsanto
• A major part of that job was
spraying Roundup or Ranger Pro (a
similar Monsanto product)... He
sprayed it 20 to 40 times per year,
sometimes hundreds of gallons at a
time on the school properties
https://www.nytimes.com/2020/06/24/business/roundup-settlement-lawsuits.html
“…contend glyphosate,
the key ingredient in
Roundup, is safe, effective
and better than available
alternatives.”
Case Report: Agent Orange
• Ecocide in Vietnam: US army
troops sprayed herbicides (2,4-D,
dioxins, etc.) over the forests to
destroy cover and food of the
Viet Cong troops
• Deaths: 400,000 (3 million
people of Vietnamese citizens
was affected)
Case Report: Terminix
• A boy in Florida suffered from brain
damage after Terminix fumigated a
family home for termite infestation
• …unable to control his limbs,
uncontrollable twitching and
flopping. …unable to feed himself
and speech is severely
compromised
https://pinindy.com/The-Importance-of-Handling-Solvents-Correctly.html
Solvents
Inorganic
solvents
Carbon-less solvents like
H2O, SO2, etc.
Organic
Solvents
Carbon-based solvent like
toluene, benzene, hexane,
etc.
https://gfycat.com/
Hydrocarbon
solvents
Organic
Solvents
Oxygenated
solvents
Halogenated
solvents
Hydrocarbon solvents
Classified into three subgroups based on their carbon skeleton:
Aliphatic
- chain-like
- made with single or double bonds
Aromatic
- Cyclic
- Delocalized,
conjugated pi system
Paraffins (alkanes)
- chain-like, single bonds
Oxygenated solvents
Produced through chemical reactions from olefins (alkenes, carbon chain
with double bonds)
Alcohols
Esters
Ketones
Ether
Glycol ethers
Halogenated solvents
Solvents that contain a halogen such as chlorine, bromine or
iodine
Routes of Exposure and Hazards
Acute effects
Chronic effects
headache
nervous system damage
dizziness
kidney and liver damage
Eye, nose, and throat irritation
adverse reproductive effects
Lightheadedness progressing to
unconsciousness, seizures, and death
skin lesions
cancer
Mitigation Measures
• Proper ventilation
• Use of complete personal protective
equipment
Case Report: Acute organic solvent
poisoning during epoxy coating
• A 71-year-old man was found unconscious
at a construction site and immediately
transferred to the emergency room.
• There were no acute brain or cardiac lesions
that would have accounted for the
faintness. In addition, blood and urine tests
did not indicate a cause of loss of
consciousness.
• He lost consciousness as a result of acute
poisoning caused by organic solvent exposure
in a semi-enclosed space.
https://europepmc.org/article/PMC/6751803
https://americanpaintinganddecorating.com/pros-and-cons-ofepoxy-floors/
Case Report: Benzene-contaminated
toluene and acute myeloid leukemia
• A male worker, worked at the facility from 1968 until
1994. In early 2003, he was diagnosed with
pancytopenia (low count for all types of blood cells).
• In December 2003 at the age of 72 years, a bone
marrow biopsy showed acute myeloid leukemia with
multilineage dysplasia.
• Employees specify that personal protective
equipment (i.e. respirators, impervious clothing, or
gloves) were rarely, if ever, utilized when working with
the toluene solvent. The solvent was applied to a rag
or brush and used without gloves, creating both
inhalation and dermal exposures. There was no local
exhaust ventilation or other engineering controls
present in the workspace.
What is a safety data sheet?
Why do we need safety data sheets?
• Provide comprehensive information about a
substance or mixture for use in chemical
management
• Source of info about hazards, including
environmental hazards, and to obtain advice
on safety precautions
• Develop an active program of worker
protection measures, including training, which
is specific to the workplace