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:









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: http://www.thelovechef.com/kids/food_groups.html

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.