To be honest, I never thought I would have to write a blog about studying. Actually, I never thought I would have a blog at all because, well, writing was never one of my strongest point.

This is my first blog post ever and I really hope it will work out somehow.

Anyway, welcome to my place, where I share pretty much all of my thought about Environmental Health. _(:з」∠)_

Weeks 13-14: Case Study Presentations

Okay, last post of this lecture.

I found the case study really interesting. Our group got the max point (Yay for us!).  Oh and I must say my friends/group, Minh Anh, Linh, Quynh and Duy play an important role in this so thanks a lot guys.

I learnt a lot after this, especially about melamine and its legislation (that’s what my group study by the way) as well as what happens after the case. When this happened, I was in Viet Nam and our country was also affected by this but well, I didn’t pay much attention to it back then since it has nothing to do with me (bad me, I know).

I also learn new things from other groups, not many though D’:

Personally, I think the noise group did it good, same with medicine. They gave us a lot of good information (It’s not that other groups don’t give it, I just can’t catch up with their presentations, sorry guys). On the other hand, I find it really hard to give questions to other groups, it’s either too boring, hard that I can’t get it or well, I understand everything and don’t think there is anything to question others.

Summing up, I think this assignment gave us a great chance to learn more about environmental health. However, there are still some drawbacks, as the group focus too much on their presentation, they didn’t pay much attention to other presentations and I think we won’t learn much from others by this way.

That’s all. Thank you for following me after all this time. I hope you manage to learn something new from my blogs. _(:з」∠)_

Week 12: Managing Environmental Health Risks: Indoor air, housing

Hey guys, I think we are getting near the end.

The topic of this week is Indoor air, and it’s also the last lecture of the course. Next week, we will be presenting and listening to the case study presentations.

To begin with, on contrary to most believe, closing the door and make your house isolated from the outside doesn’t keep the pollution away. Indoor air can have pollutants as well and if it get stuck in a place too long, well, you can imagine the harm it will bring right?

Before studying this lecture, I always thought that well, since the air outside is so polluted, it’s best if I close all the doors and protect myself from the pollution. Ha, silly right? But it’s what I had believed for years, and I think there are people beside me believe in this too.

Let’s go briefly over this topic. The sources of indoor air pollution include:

  • Combustion by-products (include CO, CO2, SO2, formaldehyde, hydrocarbons, NOx and a variety of airborne particles)
  • Microorganisms and allergens (include detergents, humidifiers, air-cooling towers, household pets,…)
  • Formaldehyde and other organic compounds
  • Asbestos fibers
  • Tobacco smoke
  • Radon

The indoor air pollution was highlighted by the so-called sick building syndrome (people living or working in certain buildings have various types of chronic ailments)

To manage this, there are some control measures:


References and further reading:

0674258592.01.MZZZZZZZ Environmental Health Revised Edition, Dade W. Moeller.


Week 11: Managing Environmental Health Risks: Ambient air pollution and noise

Before starting, I would like to note that I didn’t attend this week lesson so there may be something I miss, sorry. D”:

This week topic concerns one of the 21st Century Health Problems: Air pollution, or to be more specific, ambient air pollution (and noise).

First, let’s take a look at ambient air pollution.

Ambient air pollution come from 3 sources:

–Chemical: The contaminants come from nature or human activities include:

  • sulfur dioxide (SO2),
  • nitrogen oxides (NOx),
  • ozone (O3),
  • carbon monoxide (CO),
  • volatile organic compounds (VOC),
  • hydrogen sulfide (H2S),
  • hydrogen fluoride (HF),
  • gaseous forms of metals


–Physical (Particles)

Have you ever wondered how polluted your city is? Don’t worry, AQI is here to help you, this website is up to date and really informative.


So anyway, how do you manage this problem? According to some information I found, “the best way to control air pollution is to prevent it in the first place, by altering the processes that produce it or by substituting nonpolluting substances for those that generate contaminants”

Some controls can be implemented on a generic basic while other must be tailored to a wide range of characteristics. Managing the air pollution includes this approaches:

  • Atmospheric dilution: The dilution capacity of the local atmosphere is used to reduce the concentrations of a pollutant to an acceptable level
  • Substitution or limitation: This approach either eliminates the pollution or limits the amounts of key chemical elements available for pollutant production
  • Reduction in quantity produced
  • Process or equipment change
  • Air-cleaning technology

Next is noise pollution.

Noise is, basically a “sound, especially of a loud, harsh, or confused kind:” or a “a sound of any kind“, according to Dictionary. Personally, I found noise is kinda hard to define. It can be any sound that annoy you. For instance, when a person is happy, they find rock music is pleasant to hear but when they are stress or tired, that kind of music become annoying, so it’s noise. It’s really confuse me when thinking about this as how can I know if the sound I make is noise or not? Will it annoy people?

The pictures below show how noise affect human health and life.

Kết quả hình ảnh cho effect of noise pollution

Figure 2: Auditory and extra-auditory effects of noise

To control noise, there are legislation and laws that protect people from noise pollution. For example, in Finland:

  • Residential areas (LAeq)

–Between 7-22 (daytime) should not exceed 55 dB

–Between 22-7 (nighttime) should not exceed 50 dB, on new areas 45 dB.

  • Recreanational areas (camping sites, natural reserves…) (LAeq)

–Between 7-22 (daytime) should not exceed 45 dB

–Between 22-7 (nighttime) should not exceed 40 dB.

You can also manage noise by:

  • Remove or minimize the source: Control of specific activities that cause noise, e.g.

– Environmental permit requirements

– Permissible Sound Levels for vehicles, machinery…

  • Remove or minimize the pathway (it’s kinda impossible so maybe we can skip this)
  • Remove or minimize the exposure, e.g.:

– Land Use planning

– Environmental Impact Assessment

– Environmental Permit


References and further reading:;year=2014;volume=16;issue=73;spage=427;epage=436;aulast=Yuen

0674258592.01.MZZZZZZZ Environmental Health Revised Edition, Dade W. Moeller.

Week 8 and 10: Managing Environmental Health Risks: Food

Hello everyone, it’s been a long time since my last post eh? Almost a month if I’m not mistaken. Don’t worry, I’m back again _(:з」∠)_

Before we start with this week topic, please read the small warning below.









Okay I admit, that warning is just to throw you off since I won’t write much in this topic. Why? ‘Cause even if you don’t mind losing your appetite, I do. (And because I’m lazy)

Enough fooling around, let us get to the main point aka the topic of this week: FOOD.

I’m sure that good food is something most people can’t resist, I certainly won’t. Depending only the property of food, it was divided into groups:

Kết quả hình ảnh cho food group

Further reading:

Temping, isn’t it? But there are hazards in the food you consume daily, you know?

Let’s talk about chemical hazards first.

In food production and processing, chemical contamination can happen at any stage. Chemicals can be quite helpful, especially when it comes to food production (like pesticide on vegetables) but if the amount was not controlled it can be quite dangerous. Chemical factors in food can be sorted into 3 categories:

  • Naturally occurring chemicals: “These are toxins produced by plants, animals or microorganisms (ex: aflatoxins in peanuts, poisonous neurotoxins in mushrooms, scrombotoxins in fish).”

⇒ May cause food poisoning symptoms or intoxications.

  • Intentionally added chemicals: These chemicals are intentionally added to food at some point during the food’s growth and distribution. They are safe when used at established safe levels but if they exceed this level, they can be really dangerous.
  • Unintenionally or incidentially added chemicals: These chemicals are incidentially added to food. Most incidental chemicals have no effect on food safety, and others are only a concern if they are present in too high an amount.Kết quả hình ảnh cho intentionally added chemicals in food

Further reading:

After chemical, the next hazards may appear in food is physical hazards.

Physical hazard is any extraneous object or foreign matter in a food item which may cause illness or injury to a person consuming the product. These foreign objects include, but are not limited to bone or bone chips, metal flakes or fragments, injection needles, BB’s or shotgun pellets, pieces of product packaging, stones, glass or wood fragments, insects or other filth, personal items, or any other foreign material not normally found in food products.” Personally, beside bones, I found other physical hazard is quite unlikely to appear in food but hey, unlikely doesn’t mean it’s impossible so just keep this in your mind and be carefully when eating especially if you eat outside alright?

Last but not least is microbiological hazards. You may fell familiar with terms like yeasts, molds, bacteria, viruses and protozoa since microorganism are so widespread, there are no way you can completely avoid them. However, please remember it is important to understand when to be concerned about them and how to deal with them.

Some microorganism can be good for your health or even make food better if you use them right but some (particularly pathogens) can spoil your food. Spoiled food are extremely undesirable and need to be avoid at all cost as will cause bad effect or even disease to your health.

Food risks can be manage by legislation. For instance:

Further reading:

Cover image  Food Safety Management: A Practical Guide for the Food Industry. Edited by:Yasmine Motarjemi and Huub Lelieveld 

0674258592.01.MZZZZZZZ Environmental Health Revised Edition, Dade W. Moeller.

Week 7: Managing Environmental Health Risks: Bathing water

Hello again, readers!

The lesson of this week is about water. No, it’s not like the one we learnt last week. The water of this week is not potable water but bathing water. Meaning? It’s water used for bathing and swimming, not for drinking so don’t expect to drink this kind of water, okay? Good.

Bathing water can be divided into 2 types: (Outdoor) Bathing water and Pool water.

First, let’s talk about outdoor bathing water. This type of water is natural water (lake, river, beach, blah blah blah) and can be easily polluted with hazards like pathogens or discharges from sewage, nutrient inputs (which may lead to eutrophication and facilitate a massive growth of algae), Cyanobacteria, surface run-off, faeces,…. As a result, fever, diarrhea and vomiting or other severe health problems may appear on those who came in contact with this type polluted water. Okay that may sound like I’m making things up, there’s no way outdoor bathing water could be that bad right? WRONG! Don’t underestimate the danger of outdoor bathing water, especially if you are living in a bad environment. You know, in my country, nah that’s too big, in my city, most people don’t dare to bath in outdoor bathing water such as lake or river because those are really polluted. Just imagine, everyday, tons of sewage and garbage are thrown into a river, would you dare to bath in that river? ‘Cause that’s what happen in my city.

Next is pool water. Have you ever gone to a swimming pool? I’m sure that most of you have, at least once. Then do you know what type of hazards are there in the swimming pool? The picture below will show you.

Kết quả hình ảnh cho chemicals in pool, hot tub and spa water

Scary, right? Oh and don’t forget about the Microbiological hazards people brings to the pool when they come to use it, it can also cause direct impact on the skin, eyes and mucous membranes, or just put it simply, bad effect for your health.

However, don’t be too worry, there are ways to treat bathing water as well as laws for bathing water quality standards (otherwise nobody would dare to bath at all 😛 ).

In Europe, there are “Legal Obligations under the EU Bathing Water Directive 2006/7/EC:

  • Two main parameters used to monitor and assess the quality of bathing waters and to classify them:

– intestinal enterococci

– escherichia coli

  • Other parameters could be taken into account, such as the presence of cyanobacteria or microalgae.”

Moreover, bathing water is monitored yearly by Member States and base on their quality, bathing water are classified into 4 types: poor, sufficient, good and excellent. Therefore, you can find which place is suitable for bathing outdoor.

As for pool water, you can find your answer in this picture.

References and further reading:


That’s all for today I guess.

Alla prossima, ciao.


Week 6: Managing Environmental Health Risks: Potable water

Welcome to this week topic: Potable water. I must say, this is an interesting topic as potable water is one of the most important thing in our daily life. We can’t live without water. In fact, “water is your body’s principal chemical component and makes up about 60 percent of your body weight, every system in your body depends on water”. Moreover, various studies show that you need to consume at least 2 litters of water per day. So well yeah, potable water is important.

To start with, you probably wonder what is potable water, right? Potable water, also known as drinking water, is water that suitable for human consumption.

There are 2 main sources of potable water:

  • Groundwater/artificial groundwater
  • Surface water


Groundwater Surface water
Characteristics •Fresh water in the rock and soil layers beneath Earth’s land surface.

•Makes up more than one-fifth (22%) of Earth’s total fresh water supply

•Determined by the geology of the area

•Move slower

•Found over the land surface in streams, ponds, marshes, lakes or other fresh water sources.

•Move faster

Contamination Occurs when products such as gasoline, oil, road salts and chemicals, pharmaceuticals… or microbes due to poorly managed waste water treatment get into the groundwater. Can be affected by numerous physical variables such as

•topography, land cover,

•soil conditions, mineralogy, and ground-water conditions.

Contains microorganisms and bacteria.

Less contaminated due to natural filter More easily contaminated

Since groundwater and surface water are interconnected, the contaminants may share between these two. Moreover, neither of water source can ever be entirely free from water contaminants.

To determine water quality, you need to consider physical, chemical and microbiological properties of water. More information can be found here.

Next part of the lesson, we learn about water treatment.

Water treatment is “the act or process of making water more potable or useful, as by purifying, clarifying, softening, or deodorizing it.”

This treatment usually deals with viruses, bacteria, parasites and with changing physical characteristics such as turbidity, chemical contaminants (oil or gasoline residue, pesticides and herbicides) and organic material.

However, in my country, water treatment was sadly not being paid the attention it deserves. As a result, people in my country can only drink water from a bottle or boil water from the tap but not directly from the tap like in Finland.

References and further reading:

0674258592.01.MZZZZZZZ Environmental Health Revised Edition, Dade W. Moeller.

Week 5: Risk Assessment and Management

Okay so you know about the Environmental Health Hazards, right? I talked about it in the previous blog. This time, we will get to learn more about the Risk Assessment and Management, sound exciting isn’t it? XD

Managing Risks includes 3 following steps:

  1. Identification of hazards (This was what we learnt last week)
  2. Assessing the risk level (this contains two types: Likelihood and Severity of impact)

So yeah, in this step, you need to analyze and decide on how likely it is for the risk to happen as well as how severe the risk is on a scale of 1 to 5. The risk is calculated by multiplying the Likelihood with the Severity. You can find it in the table below how high the risk is after calculating, with 1 being insignificant in consequences and rare in likelihood.

Kết quả hình ảnh cho risk assessment

My group did a risk rating on Artificial colors and this is our result:


Scale 1-5 1. Insignificant 2.  Minor 3. Moderate 4. Major 5. Catastrophic
Likelihood 5. Almost certain
4. Likely
3. Moderate


2. Unlikely
1. Rare
      According to the result, our risk rating is: 3*3 = 9, which is HIGH.
    3. Deciding on the risk management option

There are 5 options can be used to influence the source, the pathway, the exposure or a combination simultaneously.

Kết quả hình ảnh cho hierarchy of hazard control

References and further reading:

0674258592.01.MZZZZZZZ Environmental Health Revised Edition, Dade W. Moeller.

Week 4: Environmental Health Hazards

In this week lesson, we get to learn about Environmental Health Hazards in detail. There are three types of hazards: Chemical Hazards; Microbial Hazards; Physical and other Hazards. We also learn about the definition of NOEC and LC50.

NOEC (no observed effect concentration) means the test concentration immediately below the lowest tested concentration with statistically significant adverse effect. The NOEC has no statistically significant adverse effect compared to the control.” (GHS Glossary)

LC50: “LC stands for “Lethal Concentration”. LC values usually refer to the concentration of a chemical in air but in environmental studies it can also mean the concentration of a chemical in water.

According to the OECD (Organisation for Economic Cooperation and Development) Guidelines for the Testing of Chemicals, a traditional experiment involves groups of animals exposed to a concentration (or series of concentrations) for a set period of time (usually 4 hours). The animals are clinically observed for up to 14 days.

The concentrations of the chemical in air that kills 50% of the test animals during the observation period is the LC50 value. Other durations of exposure (versus the traditional 4 hours) may apply depending on specific laws.” (Canadian Centre for Occupational Health and Safety)

*LD50: “LD stands for “Lethal Dose”. LD50 is the amount of a material, given all at once, which causes the death of 50% (one half) of a group of test animals. The LD50 is one way to measure the short-term poisoning potential (acute toxicity) of a material.

Toxicologists can use many kinds of animals but most often testing is done with rats and mice. It is usually expressed as the amount of chemical administered (e.g., milligrams) per 100 grams (for smaller animals) or per kilogram (for bigger test subjects) of the body weight of the test animal. The LD50 can be found for any route of entry or administration but dermal (applied to the skin) and oral (given by mouth) administration methods are the most common.” (Canadian Centre for Occupational Health and Safety)

  1. Chemical Hazards.

As you know, from the previous posts, there are three ways of exposures:

  • Oral: expose to chemical contaminants through drinking water or food.

For example, in Vietnamese food, people usually use “fish sauce” as in ingredient. Our group did a research on this and here is what we found:


During this research, I found out so many things. It surprised me that the food we consume daily could contain so many chemicals, both good and bad for our health.

  • Dermal: expose to chemical contaminants through your skin or basically everything you touch.

You can be expose to chemical hazards easily through dermal in a way you least imagine. Chemical hazards appear in your daily life through various form: in a cosmetic you use, in the clothes you wear, in the detergent you use for washing/cleaning things, ect.

  • Inhalation: expose to chemical contaminants through breathing.

You would be surprised to see how polluted the air you breath in is, whether it’s indoor or outdoor.

In fact, you can see it in the Air quality index. This page show you the current air quality in every country in the world at the current time, which is really convenient.

To know how good the air in your city is, you can compare the statistic with this table

AQI Air Pollution
Health Implications
0–50 Excellent No health implications.
51–100 Good Few hypersensitive individuals should reduce outdoor exercise.
101–150 Lightly Polluted Slight irritations may occur, individuals with breathing or heart problems should reduce outdoor exercise.
151–200 Moderately Polluted Slight irritations may occur, individuals with breathing or heart problems should reduce outdoor exercise.
201–300 Heavily Polluted Healthy people will be noticeably affected. People with breathing or heart problems will experience reduced endurance in activities. These individuals and elders should remain indoors and restrict activities.
300+ Severely Polluted Healthy people will experience reduced endurance in activities. There may be strong irritations and symptoms and may trigger other illnesses. Elders and the sick should remain indoors and avoid exercise. Healthy individuals should avoid outdoor activities.
Concentration, micrograms per kubic meter air, µg/m3
Index classification SO2 NO2 PM10 PM2.5 O3 CO TRS
good below 20 below 40 below 20 below 10 below 60 below 4000 below 5
satisfactroy 20-80 40-70 20-50 10-25 60-100 4000-8000 5-10
fair 80-250 70-150 50-100 25-50 100-140 8000-20000 10-20
poor 250-350 150-200 100-200 50-75 140-180 20000-30000 20-50
very poor above 350 above 200 above 200 above 75 above 180 above 30000 above 50

2. Microbiological Hazards

There are 6 types of Micro-Organisms:

  • Bacteria
  • Viruses
  • Protists (animal and plant like)
  • Algae
  • Fungi (yeasts and molds)
  • Prions

These micro-organisms are practically everywhere around you. You can also be exposed to it through oral, dermal and inhalation.

For further reading, you can try these pages:

3. Physical and Other Hazards

Beside chemical and biological, you can also be exposed to physical hazards such as dust, noise, vibration, radiation, temperature, moisture, ect.

Further information can be found here: (personally, I think this page has a lot of useful information, maybe you can find something you need here XD )

Week 3: Factors of Environmental Health, Legal Framework.

This week lesson is about factors of Environmental Health (again) and Legal Framework.

There are 4 factors of Environmental Health: Chemical, Physical, Microbiological and Other. These factors affect our health through 3 ways: Oral, Dermal and Inhalation. For example, you can be exposed to Chemical factors through oral way by drinking water. As water may contains many chemical hazards, if it was not carefully deal with, when you drink water, you will be exposed to those chemical hazards which can cause bad effect to your health.

Here is an example for the Environmental Health factors in my life.


For further information, you can read it here:

About Legal Framework, each country has their own legislation and ministry. In my country, Vietnam, the task of supervising Environmental issues lay on the Ministry of the Natural Resources and Environment. They mainly deal with soil resource, water resource, land management, sea and island as well as climate change. However, when it comes to health issues, Ministry of Health in Vietnam is the one who will take responsibility.

Nowadays, we have to face lots of environmental issues, which will, sooner or later, affect our health such as Pollution, global warming, climate change, etc and I think Ministry as well as every of us play an important role in preventing or solving these issues. Further information can be found here.


Week 2: Introduction to Environmental Health

This is my first lesson in Environmental Health and, well, I can say that even though I’m not sure what or how much information will stuck in my mind after this course, the first lecture did make a strong impression on me.

At the beginning, we got to learn about Environmental Health definition. According to Wikipedia, “Environmental health is the branch of public health that is concerned with all aspects of the natural and built environment that may affect human health.” or to put it simply Environmental Health is the interaction between human and the environment.


The lesson continue with us discussing about aspects of the environment that adversely affect our health. There are actually lots of aspects in the environment that affect our health, for instance air, food, water, noise and so on. However, we can divide these into 4 main factors:

  • Chemical (hazadous subtances)
  • Physical (noise, dust, radiation, …)
  • Microbiological (virus, microbes, …)
  • Others

These factors affect our health through 3 ways: Oral, Dermal, and Inhalation. And the factors can come from anywhere, nature, in the air, in the water,  from the fatories, industry, human activities,… (Basically, you can be influenced just by breathing or standing and not doing anything D:) 


And in order for our health to be effected, 3 things are needed:

  • Source
  • Pathway
  • Exposure route

These things are also known as Environmental Health risks. Oh and if you wonder, Risk is “a probability or threat of damage, injury, liability, loss, or any other negative occurrence that is caused by external or internal vulnerabilities, and that may be avoided through preemptive action.” according to Businessdictionary. The Environmental Health Risks always go together so if one of three things is missing then congratulation, your health is safe! XD

Continue with the lesson, we learn about how to manage the risk. It includes these steps: first, you need to identify the hazards, then start to rate the risk by multiply the likelihood with severity. After rating, you can choose the best risk managing option.


Last but not least, we learn about Epidemiology and Toxicology.

Toxicology is “a science that deals with poisons and their effect and with the problems involved (such as clinical, industrial, or legal problems)”

Epidemiology is “the study of the distribution and determinants of health-related states or events (including disease), and the application of this study to the control of diseases and other health problems. Various methods can be used to carry out epidemiological investigations: surveillance and descriptive studies can be used to study distribution; analytical studies are used to study determinants.”

However, from what I understand, toxicology seems to focus more on the individual while epidemiology focus more on the public. Anyway, there is one thing I found really interesting when learning this. There is only a thin line between a medicine and a poison. To be more specific, if you use just enough, it’s medicine but if you use it too much, it’s poison.



0674258592.01.MZZZZZZZ Environmental Health Revised Edition, Dade W. Moeller.