Comment by skywhopper | Hacker News Reader

Comment by skywhopper | Hacker News Reader

I have no doubt these ships pollute really badly. That said, this is poor reporting. The numbers given in the article are impossible to make sense of as given. We get some particulate numbers for directly outside and around the ship's funnels and comparative numbers for Piccadilly Circus. But even assuming these numbers are fairly collected, that doesn't really tell us all the information we need.

The article implies this means vacationers are getting a bum deal if they are looking for cleaner air, and that ship staff might be in danger from exposure to these particulates as well. But there's no information on how often staff or vacationers are in these high-particulate zones. And there's no corresponding numbers for other parts of the ship. What about on state room balconies? Or the pool area? Or staff quarters? My wild guess is that the numbers would be significantly better than Piccadilly most places on the ship, but this article doesn't tell me if I'm right or wrong about that.

As for the "as much particulate matter as a million cars", that sounds bad, but what does it mean? Is it a million cars operating 24/7? Given that they say 30 cruise ships equal all the particulate pollution from cars in the entire UK, I'm guessing they mean a million cars' typical daily routine. Which would be what, a couple of hours at most of operation?

And then, the ship is serving as living quarters for the people aboard. So how much particulate matter is generated by electricity generation and other fuel usage of a typical home? What's the difference in those usages when people are occupying the residence versus when they are on a vacation? For that matter, how does cruise ship vacation pollution generation compare to pollution generated by other vacation modes?

Sure you can't answer all of that in one article or one study, and while I fully accept cruise ships are "wasteful" in some sense, and are definitely not a positive impact on the environments they travel through, it's important to give a full picture of the situation.

(The article is from 2017 by the way.)

Also, its worth noting that cars have diesel particulate filters (otherwise they wouldn't be allowed into that part of london).

From what I understand (which isn't a whole lot), those particulate filters are a lie. They DO NOT reduce emission of particulate matter. Instead, at low exhaust temperature (such as crawling through a city), they collect the particulates, then at higher engine temperatures (such as cruising on the highway) they release them - a process they call 'regeneration'. i.e. they just move the pollution out of the city.

> They DO NOT reduce emission of particulate matter.

Well not exactly. Depending on the type of filter the collect particulate matter and when they have collected enough to need a regeneration process they use passive heat (because driving on the highway make the filter heat up) or the actively heat the filter to then burn up most of this particulate matter. It is like self cleaning ovens that get hot enough to nearly burn all what is in them.

So about 5% of the particulate matter isn't being able to be filtered out that way. Either because the particles are to small for the filter to initially block them. Or because the regeneration leaves them as a kind of residue. Also not everything can be "burned up" so that these filters have a limited lifetime of somewhat below 200.000 kilometers.

I know, I glossed over lot's of important details, but at least be assured, that not all filtered particulate matter is being released in the countryside.

Thank you. I was clearly misinformed on this matter.

Not really arguing with any of the points you made, except that I think answer all or most of those questions you posed _could_ (and dare I say should) have been answered in one study. That would be my definition of good, thorough reporting (so Im pointing the finger at the article writer and what counts as "reporting" these days).

Does particulate pollution even matters when you are thousands of miles away from cities and humans?

I would be very much interested if working on a cruise ship for a season (9 months) would decrease my life expectancy.

It depends on the job. Are you talking about cabin crew or below deck?

Up top you have to worry about suicide, "rogue waves" and a general lack of accountability at sea.

Below deck you're exposed to so many carcinogens and industrial solvents you're guaranteed a miserable death by cancer. These crews are always staffed by people who wouldn't understand an MSDS if you handed it to them. Same with airport runway personnel.

9 months may not be enough time for that though unless you sit around huffing ship paint with no mask.

It's actually a musician role I'm auditioning for. Bassist. I'm also kind of worried about carpel tunnel, but I've still yet to pass the audition. :-)

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