Is Japan full of polution?

[blimp]

Originally Posted by MMM

What conclusions do you make from this data, Blimp?

my very personal conclusion of the data is that the air pollution is worse (not necessarily bad) for the three mentioned japanese cities than i thought. now, may i ask the reason behind you asking me for my conclusion?

[MMM]

Originally Posted by blimp

my very personal conclusion of the data is that the air pollution is worse (not necessarily bad) for the three mentioned japanese cities than i thought. now, may i ask the reason behind you asking me for my conclusion?

I asked because it wasn't obvious to me what kinds of conclusions I should come up with lists of numbers and population densities of a bunch of cities around the world. In short, the link didn't mean much to me, so I was wondering what it meant to you.

[Nyororin]

Originally Posted by blimp

my very personal conclusion of the data is that the air pollution is worse (not necessarily bad) for the three mentioned japanese cities than i thought. now, may i ask the reason behind you asking me for my conclusion?

Thinking about it, I have to wonder a bit - how are they taking this data? And where? Because if the air quality in Tokyo is anything like the air quality in Nagoya - there are areas with great crystal clear air, and areas with an abundance of factories that aren`t that great. It varies a LOT with location.

If they are only taking a few samples around the city and averaging them - or (doubtful) taking a single sample somewhere... Then things could look drastically worse or better than reality.

I know the air in my little town is very very clean, as they test the crap out of it every single week or so. There is a trash incinerator nearby, and the deal with the city is that they`ll only allow it to be here if there is NO increase in pollution. This serious testing by the town has had the effect of making everywhere else around be conscious of their pollution... And the air is great at this point.

[blimp]

Originally Posted by MMM

I asked because it wasn't obvious to me what kinds of conclusions I should come up with lists of numbers and population densities of a bunch of cities around the world. In short, the link didn't mean much to me, so I was wondering what it meant to you.

ok....
first, the document connected to the link i sent mentions nothing about population densities, so i am not sure what list you are looking at. second, the list has apart from population for each listed city also three variables (perhaps this what you refer to as "numbers") that hopefully* gives a relatively good picture of the air quality of the city in question.

*i say hopefully since i am not an expert on air pollution or air quality, but will have to take the authors' word that these are indeed good indicator for air pollution.

[MMM]

Originally Posted by blimp

ok....
first, the document connected to the link i sent mentions nothing about population densities, so i am not sure what list you are looking at. second, the list has apart from population for each listed city also three variables (perhaps this what you refer to as "numbers") that hopefully* gives a relatively good picture of the air quality of the city in question.

*i say hopefully since i am not an expert on air pollution or air quality, but will have to take the authors' word that these are indeed good indicator for air pollution.

You are right...population, not population densities.

I ask because without knowing what a "good number" or a "bad number" is, it is hard for me to know what the numbers mean. So Tokyo has less particulate matter than Athens, but a higher population. But is has 7 times the population of Bogota but more particles per 1000.

I am not being lazy when I say it is hard for me to know what these numbers MEAN, as I am not sure what population adds to the equation, besides number of people in "danger". And what is population without population density or the city's actual size?

[blimp]

Originally Posted by Nyororin

Thinking about it, I have to wonder a bit - how are they taking this data? And where? Because if the air quality in Tokyo is anything like the air quality in Nagoya - there are areas with great crystal clear air, and areas with an abundance of factories that aren`t that great. It varies a LOT with location.

If they are only taking a few samples around the city and averaging them - or (doubtful) taking a single sample somewhere... Then things could look drastically worse or better than reality.

I know the air in my little town is very very clean, as they test the crap out of it every single week or so. There is a trash incinerator nearby, and the deal with the city is that they`ll only allow it to be here if there is NO increase in pollution. This serious testing by the town has had the effect of making everywhere else around be conscious of their pollution... And the air is great at this point.

some answers to your questions can be found in the column to the right, "about the data".

Originally Posted by MMM

You are right...population, not population densities.

I ask because without knowing what a "good number" or a "bad number" is, it is hard for me to know what the numbers mean. So Tokyo has less particulate matter than Athens, but a higher population. But is has 7 times the population of Bogota but more particles per 1000.

I am not being lazy when I say it is hard for me to know what these numbers MEAN, as I am not sure what population adds to the equation, besides number of people in "danger". And what is population without population density or the city's actual size?

i didn't know either what a good or bad number was, but it says in the column to the right that:
The current World Health Organization (WHO) air quality guidelines are annual mean concentrations of 20 micrograms per cubic meter for particulate matter less than 10 microns in diameter (PM10) and 40 micrograms for nitrogen dioxide and daily mean concentrations of 20 micrograms per cubic meter for sulfur dioxide.

concerning the population figure, i don't know, your guess is as good as mine. however, when i made my conclusion i disregarded the population data, since it has no bearing on the question "is japan polluted?". now, air pollution is only one factor to the overall picture, so perhaps someone else can contribute by finding other factors and data for these.

[godwine]

But we are still only looking at strictly from air pollution's perspective though right? Water quality and audible quality is not considered?

[Nyororin]

Originally Posted by blimp

some answers to your questions can be found in the column to the right, "about the data".

Unfortunately that doesn`t really help.

Japan doesn`t quite have the same sort of zoning limitations as a lot of other locations, so a "residential" area doesn`t necessarily mean that every 4th building is a mini factory or business.

I don`t mean to imply that their data is wrong, or that it isn`t accurate. I just am sort of wondering aloud how they calculated this, as Japan is a hard place to measure due to the way cities are mixed.

[blimp]

Originally Posted by Nyororin

Unfortunately that doesn`t really help.

Japan doesn`t quite have the same sort of zoning limitations as a lot of other locations, so a "residential" area doesn`t necessarily mean that every 4th building is a mini factory or business.

I don`t mean to imply that their data is wrong, or that it isn`t accurate. I just am sort of wondering aloud how they calculated this, as Japan is a hard place to measure due to the way cities are mixed.

i don't know how well these quotes answers your question but it is the best i could do with my limited knowledge.
The data on sulfur dioxide and nitrogen dioxide concentrations are based on reports from urban monitoring sites. Annual means (measured in micrograms per cubic meter) are average concentrations observed at these sites. Coverage is not comprehensive because not all cities have monitoring systems.

The data on concentrations of particulate matter are estimates, for selected cities, of average annual concentrations in residential areas away from air pollution “hotspots,” such as industrial districts and transport corridors.

could you pls elaborate on the last sentence in your post. the sentence ending with "....., as Japan is a hard place to measure due to the way cities are mixed."

[Nyororin]

Originally Posted by blimp

could you pls elaborate on the last sentence in your post. the sentence ending with "....., as Japan is a hard place to measure due to the way cities are mixed."

In a lot of countries, there are some pretty strict rules in place about where you can build homes, factories, etc. The US is a very good example - being split very clearly into residential, industrial and commercial areas.

Japan, however, is much more loose when it comes to zoning. Heavy industry is pushed off into certain areas, as is some commercial... But otherwise, as long as you follow the construction rules for the land plot you can build pretty much anything. So you will find extremely mixed neighborhoods - single family homes next to a factory next to a huge condo complex next to a small farm next to a one story business next to a ... etc etc etc.

In some areas those factories will generate more pollution than others. So in my opinion, it is very hard to find a solely residential area in order to get a reading. You`d pretty much always be in a mixed area, and not all mixed areas are equal in their air quality. And if they did manage to find a residential only area, chances are it`s an extreme exception so would not be accurate for the majority of residences.