<META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1">
<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:x="urn:schemas-microsoft-com:office:excel" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"><head><meta name=Generator content="Microsoft Word 15 (filtered medium)"><style><!--
/* Font Definitions */
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
{font-family:Consolas;
panose-1:2 11 6 9 2 2 4 3 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0cm;
margin-bottom:.0001pt;
font-size:12.0pt;
font-family:"Times New Roman",serif;
color:black;}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
p
{mso-style-priority:99;
mso-margin-top-alt:auto;
margin-right:0cm;
mso-margin-bottom-alt:auto;
margin-left:0cm;
font-size:12.0pt;
font-family:"Times New Roman",serif;
color:black;}
pre
{mso-style-priority:99;
mso-style-link:"HTML Preformatted Char";
margin:0cm;
margin-bottom:.0001pt;
font-size:10.0pt;
font-family:"Courier New";
color:black;}
span.HTMLPreformattedChar
{mso-style-name:"HTML Preformatted Char";
mso-style-priority:99;
mso-style-link:"HTML Preformatted";
font-family:Consolas;
color:black;}
span.EmailStyle20
{mso-style-type:personal-reply;
font-family:"Calibri",sans-serif;
color:#1F497D;}
.MsoChpDefault
{mso-style-type:export-only;
font-size:10.0pt;}
@page WordSection1
{size:612.0pt 792.0pt;
margin:72.0pt 72.0pt 72.0pt 72.0pt;}
div.WordSection1
{page:WordSection1;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]--></head><body bgcolor=white lang=EN-CA link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US'>Dear Ron<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal style='margin-bottom:12.0pt'><b><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>></span></b>It appears that the parameters for the WHO PM2.5 standard is 2mg/min of _what_ _burning_ _level_ (i.e., we need a wattage parameter of some type)? <span style='color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal style='margin-bottom:12.0pt'><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>Well, they have taken the EPA outdoor air quality approach as applied to the EPA version of space heating stoves (which limits total emissions per home, the way New Zealand does) and then projects that onto cooking stoves, as if all stoves were of the same fire power. As you noted, the flaw is fundamental.<o:p></o:p></span></p><p class=MsoNormal style='margin-bottom:12.0pt'><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>Consider: We have typical homes in Java owning 4 stoves or more, as many as 7, with a wide range of firepowers. Which one is the allowed version? If the WHO <i>model</i> of exposure (it is not based on measurements) assumes stoves can’t be clean enough at <i>some</i> high power level, then inappropriate conclusions will be drawn about all stoves. Even if the exposure and disease response modelling were correct, someone with a small filthy stove would be allowed and large stoves would not even if very clean burning per useful MegaJoule. Thus we have a fundamental conflict between the WHO’s approach to health and the ratings provided by nearly all stove tests.<o:p></o:p></span></p><p class=MsoNormal style='margin-bottom:12.0pt'><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>There are two catches to this – one I just raised with Dean. The first is the idea that there are ‘clean fuels’ that will not emit PM, or as much anyway. The other is that there are ‘clean stoves’ that will not emit much PM. Huh? If the emissions are related to the <i>combination</i> then any such attribution is incorrect and ultimate meaningless (or grossly misleading). We cannot attribute to a stove something ‘achieved’ by the fuel’. I won’t repeat all that – anyone who missed it, please read my message to Dean.<o:p></o:p></span></p><p class=MsoNormal style='margin-bottom:12.0pt'><span style='color:#1F497D'>></span>When an Italian university study concluded that an average unfiltered cigarette at human-puffing speed (i.e., smoked in around 5 minutes) produced more particulate than a modern, properly running 250KW diesel engine fully loaded for an hour, it is important to link those 2 mg with an amount of fuel combusted in that minute, don't you agree? <span style='color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal style='margin-bottom:12.0pt'><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>Prof Lodoysamba in Ulaanbaatar was pointing out that even though their ambient PM level is decried, often reaching 1500 µg/m<sup>3</sup> in winter, annual PM<sub>2.5</sub> exposure is not as bad as living in a home with a single smoker.<o:p></o:p></span></p><p class=MsoNormal style='margin-bottom:12.0pt'><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>I take your point about the exposure dose v.s. the total exposure. As disease response is dose related, this is a major issue when determining the effect of stoves. If a stove emits a little PM all the time, it may have no effect at all. The same total emissions in an ignition period alone might have a significant effect. Knowing only the total PM mass emitted cannot give a very good prediction of health effects.<o:p></o:p></span></p><p class=MsoNormal style='margin-bottom:12.0pt'><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>Here is a contribution to our discussion from a friend who works in this (health) field:<o:p></o:p></span></p><p class=MsoNormal style='margin-bottom:12.0pt'><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>++++++++++<o:p></o:p></span></p><p class=MsoNormal style='margin-bottom:12.0pt'><span style='background:#FFF2CC'>If you ignore concentrations and exposures -- i.e., the real determinants of disease - then fuel cycle emissions anywhere anytime become culprits in disease. Remember, all the GBD [Global Burden of Disease] calculations begin with fictitious fuel quantities, qualities, and aggregate locations; then dubious emission factors are applied and the output put through even more dubious atmospheric circulation models to cook up some concentration panels in the model grids - maybe 20 km x 20 km, I don't know. Then put in some rats - I mean people - in the grid, to calculate, for example, how many pregnant women 12-15 are mulling about outside and how many are cooking with fictitious wood in fictitious homes at what times; do the same for the rest of the population as well, and with fictitious data about their health, height, weight, age, maybe even length of the earlobe (just get a PhD kid to establish some correlations and three papers are ready to roll). <br><br>The rest is easy. Fictitious dose-response matrices and before you know it, you've got an e-mail!! Your paper has been accepted for publication in Science! In Nature! </span><o:p></o:p></p><p class=MsoNormal style='margin-bottom:12.0pt'><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>++++++++++<o:p></o:p></span></p><p class=MsoNormal style='margin-bottom:12.0pt'><span style='color:#1F497D'>></span>P.S. Somehow I seem to be getting a feeling that the WHO standard is not being chosen for proven health purposes, but rather for certain types of fuels to be ultimately shown to be by definition "too dirty". <span style='color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal style='margin-bottom:12.0pt'><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>The WHO is not exactly a Standard in the way we are talking about it – they have a standard for annual, 24 and short term exposure; that is true. But when calculating the effect of exposure based on the mass of PM emitted per minute from a stove, that is not a standard, that is an exposure model. The relevant document agrees that its single box model is not representative of actual exposure because air does not move like that. Well, OK, they discuss the limits of the model. They did not fix it and the exposure calculations are at best dubious for that reason alone. Nigel Bruce (who might be reading this list) and Nate Johnson said they are going to work on improving the exposure models.<o:p></o:p></span></p><p class=MsoNormal style='margin-bottom:12.0pt'><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>The main input value to the model is the PM emitted by the stove per minute, but not for any ‘maximum’ minute, for the average. So, what if the exposure and the response are not ‘average’? Kirk Smith has written enough on that to convince me the dose/response is not linear. That means we need to know the dose per time period that is meaningful such as the maximum five minute average experience during the test (or similar). <o:p></o:p></span></p><p class=MsoNormal style='margin-bottom:12.0pt'><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>If we use gravimetric methods to determine average emission per minute, and plug that into an admittedly unrepresentative exposure model, we have doubled the problem: misreporting the critical values of exposure and miscalculation the resulting exposure. Calibrated light scattering PM measurements can give real time calculated PM mass within 1% of the gravimetric values, even pretty cheap ones. That is why we need performance-based standards for the ISO, not some fixed method that we already know will not be able to predict disease response. Reason? Most of the money is coming into stoves because of disease claims. <o:p></o:p></span></p><p class=MsoNormal style='margin-bottom:12.0pt'><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>If the disease claims hold up to scrutiny, (not assured, apparently) so also must the solutions proposed.<o:p></o:p></span></p><p class=MsoNormal style='margin-bottom:12.0pt'><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>Regards<o:p></o:p></span></p><p class=MsoNormal style='margin-bottom:12.0pt'><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>Crispin<o:p></o:p></span></p><p class=MsoNormal style='margin-bottom:12.0pt'><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></p></div></body></html>