<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:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"><head><meta http-equiv=Content-Type content="text/html; charset=us-ascii"><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;}
@font-face
{font-family:AdvTT5235d5a9;}
@font-face
{font-family:AdvTT5235d5a9+fb;}
@font-face
{font-family:AdvTT5235d5a9+20;}
@font-face
{font-family:"AdvTT94c8263f\.I";}
@font-face
{font-family:"AdvTT94c8263f\.I+fb";
panose-1:0 0 0 0 0 0 0 0 0 0;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0cm;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri",sans-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;}
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.EmailStyle19
{mso-style-type:personal;
font-family:"Calibri",sans-serif;
color:windowtext;}
span.EmailStyle20
{mso-style-type:personal;
font-family:"Calibri",sans-serif;
color:#1F497D;}
span.EmailStyle21
{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='color:#1F497D;mso-fareast-language:EN-US'>Dear Paul and Philip<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D;mso-fareast-language:EN-US'>The “International WBT” referred to in the article is the 2009 version of the WBT 4.1.2. Readers are cautioned that there are multiple versions of WBT 4.1.2 with different calculations of output metrics in them, most significantly the “thermal efficiency”, among others.<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D;mso-fareast-language:EN-US'>The article mentions the 2009 version specifically but also refers to the IWA which references the 2011 version of 4.1.2, which was again altered in June 2012 while retaining the same version number.<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:8.0pt;font-family:AdvTT5235d5a9'>“As previous studies found that the differences in pollutant emissions between the cold start and hot start of the International WBT was small for stoves with relatively small thermal mass, an averaged value was calculated representing a value for high power performance, as speci</span><span style='font-size:8.0pt;font-family:AdvTT5235d5a9+fb'>fi</span><span style='font-size:8.0pt;font-family:AdvTT5235d5a9'>ed by the International Standard Workshop Agreement. tiered stove rating framework (</span><span style='font-size:8.0pt;font-family:AdvTT5235d5a9;color:blue'>Carter et al., 2014;Water Boiling Test, WBT Version 4.1.2, 2009; International Workshop Agreement, IWA, 2012</span><span style='font-size:8.0pt;font-family:AdvTT5235d5a9'>).”<br><br></span><span style='font-size:8.0pt;font-family:AdvTT5235d5a9;color:blue'><o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D;mso-fareast-language:EN-US'>The 2011 version was referenced in the IWA but there is also a provision in that same IWA that all test methods have to be subjected to an external, expert review before they can be used. As far as I have heard, that has not yet happened for that or subsequent versions save discussions of sections of it <a href="http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=6827753">here</a> and <a href="http://ujdigispace.uj.ac.za/handle/10210/8188">here</a> (any others?).<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D;mso-fareast-language:EN-US'>The efficiency calculation, which is the one most seriously incorrect in the WBT, is given as the <o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D;mso-fareast-language:EN-US'>The heat transferred to water in the pot which was heated from room temperature to boiling point plus the heat transferred to evaporate the water from the pot, Divided by the heat delivered by the equivalent dry fuel consumed.<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D;mso-fareast-language:EN-US'>The really mean “Divided by the heat theoretically available from the equivalent dry fuel consumed” but that is a quibble. <o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D;mso-fareast-language:EN-US'>The WBT uses the heating value of missing fuel, not the fuel needed to replicate the experiment. The Chinese WBT uses the energy contained in the fuel needed whether it is burned or not. <o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D;mso-fareast-language:EN-US'>The Chinese standards have never used the dry fuel equivalent of the energy released from the completely combusted fuel. It is a surprise therefore to see the claims first, that this is the “Overall Thermal Efficiency” (which the WBT 4.1.2 clearly does not use, it reports the Thermal Efficiency = combustion efficiency * heat transfer efficiency) and second, that both these tests use “the same” equation, which they do not. They also did not correct the efficiency calculation error in the Chinese test reported in Zhang, Y (2014) (first ‘here’ link above).<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D;mso-fareast-language:EN-US'>Then things get confusing. The Thermal efficiency, having been renamed Overall Thermal Efficiency is divided by the Modified Combustion Efficiency [MCE = CO/CO+CO<sub>2</sub>)] to calculate a proxy Heat Transfer Efficiency. As a proxy for fuel efficiency, this simply does not work with a stove that is creating char, in the same manner as using a carbon balance method to determine the volume of gases in which the emissions are carried. If you don’t burn the carbon you do not know how much energy has been released or when. That is why the carbon balance method (using a hood and dilution tunnel) often estimates that the amount of fuel burned is as little as half of what was actually used in the fire.<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D;mso-fareast-language:EN-US'>The section titled </span><span style='font-size:8.0pt;font-family:"AdvTT94c8263f\.I";color:windowtext'>“Differences among three pellet-gasi</span><span style='font-size:8.0pt;font-family:"AdvTT94c8263f\.I+fb";color:windowtext'>fi</span><span style='font-size:8.0pt;font-family:"AdvTT94c8263f\.I";color:windowtext'>er stoves”</span><span style='color:#1F497D;mso-fareast-language:EN-US'> has it that the heat transfer efficiency (produced as above) is an indicator of the fuel consumption. This has never been true for a solid-fuelled stove unless it makes zero char. The stoves tested are ‘semi-gasifiers’ meaning they will inevitably make a lot of char.<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D;mso-fareast-language:EN-US'>The thermal efficiency has never, since the world started testing wood stoves, indicated the fuel consumption which is why the WBT 3.x and 4.x lab tests keep getting pwned by the field tests. In the reported tests, a proxy heat transfer efficiency has been used instead of the thermal efficiency which makes the error even larger. It is unfortunate that the emissions were not reported on the basis of MJ of energy delivered to the pot as per (the same) IWA 2012:11 and as proposed in the Draft ISO 19867: Part 1. It would have overcome all sorts of problems associated with assessing fuel energy. They had the number as it is used to calculate the thermal efficiency.<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D;mso-fareast-language:EN-US'>There are 46 citations. If they had included a 47<sup>th</sup>, </span><span style='font-size:10.0pt;font-family:"Arial",sans-serif'>DOI:10.1109/DUE.2014.6827753</span><span style='color:#1F497D;mso-fareast-language:EN-US'> and read the bit about stove efficiency I think the whole set of comparative results would have been substantially different and the differences between results for different protocols would have all but disappeared.<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D;mso-fareast-language:EN-US'>It is worth mentioning, because it is topical, that the emissions <i>up the chimney</i> were compared with the <i>indoor</i> air quality ‘guidelines’ of the WHO which is intended for stoves that vent directly into the room, (or fugitive emissions from chimney stoves, which they say was not measured).<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:8.0pt;font-family:AdvTT5235d5a9;color:windowtext'>“However, the ERs of CO (18</span><span style='font-size:8.0pt;font-family:AdvTT5235d5a9+20;color:windowtext'>–</span><span style='font-size:8.0pt;font-family:AdvTT5235d5a9;color:windowtext'>210 mg/min) and PM</span><span style='font-size:5.5pt;font-family:AdvTT5235d5a9;color:windowtext'>2.5 </span><span style='font-size:8.0pt;font-family:AdvTT5235d5a9;color:windowtext'>(0.12</span><span style='font-size:8.0pt;font-family:AdvTT5235d5a9+20;color:windowtext'>–</span><span style='font-size:8.0pt;font-family:AdvTT5235d5a9;color:windowtext'>7.1 g/min) did not meet the ER targets for PM</span><span style='font-size:5.5pt;font-family:AdvTT5235d5a9;color:windowtext'>2.5 </span><span style='font-size:8.0pt;font-family:AdvTT5235d5a9;color:windowtext'>and CO suggested by the WHO IAQGs, being particularly too high for PM</span><span style='font-size:5.5pt;font-family:AdvTT5235d5a9;color:windowtext'>2.5</span><span style='font-size:8.0pt;font-family:AdvTT5235d5a9;color:windowtext'>. This implies that much additional improvement of these pellet stoves will be needed if they are to meet WHO ER targets.”<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D;mso-fareast-language:EN-US'>As pointed out in an earlier thread, if the emissions are vented outside, there is no need to compare them with indoor emission rates. This somewhat undermines the conclusion,<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:8.0pt;font-family:AdvTT5235d5a9;color:windowtext'>“This implies that much additional improvement of these pellet stoves will be needed if they are to meet WHO ER targets.”</span><span style='color:#1F497D;mso-fareast-language:EN-US'><o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D;mso-fareast-language:EN-US'>Those IAQG targets are for stoves venting into the room, not those fitted with chimneys.<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:8.0pt;font-family:AdvTT5235d5a9;color:windowtext'>“A total of 29% and 58% of CO ERs exceeded the </span><span style='font-size:8.0pt;font-family:AdvTT5235d5a9;color:#0070C0'>[time-based]</span><span style='font-size:8.0pt;font-family:AdvTT5235d5a9;color:windowtext'> intermediate and </span><span style='font-size:8.0pt;font-family:AdvTT5235d5a9+fb;color:windowtext'>fi</span><span style='font-size:8.0pt;font-family:AdvTT5235d5a9;color:windowtext'>nal ER targets limits of WHO IAQGs, respectively, and all of PM</span><span style='font-size:5.5pt;font-family:AdvTT5235d5a9;color:windowtext'>2.5 </span><span style='font-size:8.0pt;font-family:AdvTT5235d5a9;color:windowtext'>ERs exceeded both ER targets by approximate one order of magnitude.”</span><span style='color:#1F497D;mso-fareast-language:EN-US'><o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D;mso-fareast-language:EN-US'>So, unless the stoves were leaking >10% of their total emissions into the room, all three stoves met the WHO IAQG final targets. That is good news. <o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D;mso-fareast-language:EN-US'>This proves the first thing to do to improve human health around the world is to install good chimneys in every kitchen. Kudos to all those who are already doing that.<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D;mso-fareast-language:EN-US'>Regards<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D;mso-fareast-language:EN-US'>Crispin<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0cm 0cm 0cm'><p class=MsoNormal><span style='color:#1F497D;mso-fareast-language:EN-US'>+++++++++</span><span lang=EN-US style='color:windowtext'><o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><span lang=EN-ZA style='color:#1F497D'>Unfortunately the reference is behind a paywall.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-ZA style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-ZA style='color:#1F497D'>Prof Philip Lloyd<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-ZA style='color:#1F497D'>Energy Institute, CPUT<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-ZA style='color:#1F497D'>SARETEC, Sachs Circle<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-ZA style='color:#1F497D'>Bellville<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-ZA style='color:#1F497D'>Tel 021 959 4323<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-ZA style='color:#1F497D'>Cell 083 441 5247<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-ZA style='color:#1F497D'>PA Nadia 021 959 4330<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-ZA style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-ZA style='color:#1F497D'><o:p> </o:p></span></p><div><p class=MsoNormal><span lang=EN-ZA style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-ZA style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-ZA>On 3/17/2016 1:08 PM, Kirk R. Smith wrote:<o:p></o:p></span></p></div><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><p class=MsoNormal style='text-autospace:none'><span lang=EN-ZA style='font-size:14.0pt'>Can be downloaded from the website below/k</span><span lang=EN-ZA><o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-ZA style='font-size:13.5pt;font-family:AdvTT5235d5a9'> </span><span lang=EN-ZA><o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-ZA style='font-size:13.5pt;font-family:AdvTT5235d5a9'>Ef</span><span lang=EN-ZA style='font-size:13.5pt;font-family:AdvTT5235d5a9+fb'>fi</span><span lang=EN-ZA style='font-size:13.5pt;font-family:AdvTT5235d5a9'>ciencies and pollutant emissions from forced-draft biomass-pellet semi-gasi</span><span lang=EN-ZA style='font-size:13.5pt;font-family:AdvTT5235d5a9+fb'>fi</span><span lang=EN-ZA style='font-size:13.5pt;font-family:AdvTT5235d5a9'>er stoves: Comparison of International and Chinese water boiling test protocols</span><span lang=EN-ZA><o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-ZA style='font-size:14.0pt'>Yuanchen Chen, Guofeng Shen, Shu Su, Wei Du, Yibo Huangfu, Guangqing Liu, Xilong Wang, Baoshan Xing, Kirk R. Smith, Shu Tao</span><span lang=EN-ZA><o:p></o:p></span></p><p class=MsoNormal><span lang=EN-ZA style='font-size:14.0pt;color:blue'>Energy for Sustainable Development 32 (2016) 22–30</span><span lang=EN-ZA><o:p></o:p></span></p><p class=MsoNormal><span lang=EN-ZA style='font-size:14.0pt'> </span><span lang=EN-ZA><o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-ZA style='font-size:14.0pt'>Ab s t r a c t</span><span lang=EN-ZA><o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-ZA style='font-size:14.0pt'>Biomass fuels are widely combusted in rural China, producing numerous air pollutants with great adverse</span><span lang=EN-ZA><o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-ZA style='font-size:14.0pt'>impacts on human health. Some improved cookstoves and pellet fuels have been promoted. To evaluate the</span><span lang=EN-ZA><o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-ZA style='font-size:14.0pt'>performance of pellet-gasifier stoves, efficiencies and pollutant emissions were measured following International</span><span lang=EN-ZA><o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-ZA style='font-size:14.0pt'>and Chinese water boiling tests (WBTs). Compared with traditional stoves and unprocessed biomass fuels,</span><span lang=EN-ZA><o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-ZA style='font-size:14.0pt'>increased efficiencies and lower emissions of pollutants including carbon monoxide (CO), particulate matter</span><span lang=EN-ZA><o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-ZA style='font-size:14.0pt'>(PM), parent and derivative polycyclic aromatic hydrocarbons (PAHs) were revealed for pellet-gasifier stoves.</span><span lang=EN-ZA><o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-ZA style='font-size:14.0pt'>However, the calculated emission rates (ERs) of CO and PM2.5 cannot meet the ER targets recently suggested</span><span lang=EN-ZA><o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-ZA style='font-size:14.0pt'>by WHO indoor air quality guidelines (IAQGs). Better control of air mixing ratio and gross flow rates of primary</span><span lang=EN-ZA><o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-ZA style='font-size:14.0pt'>and secondary air supply greatly reduced emissions and increased efficiencies. Differences among testing protocols</span><span lang=EN-ZA><o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-ZA style='font-size:14.0pt'>are the key factors affecting the evaluation of stove performance. With longer burning duration and higher</span><span lang=EN-ZA><o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-ZA style='font-size:14.0pt'>power, the Chinese WBT had statistically higher efficiencies, gas temperature, and lower pollutant emissions</span><span lang=EN-ZA><o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-ZA style='font-size:14.0pt'>(p b 0.10) compared to those obtained through the International WBT. Statistically significant differences</span><span lang=EN-ZA><o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-ZA style='font-size:14.0pt'>between the two protocols indicate the need for further efforts in emission tests and methodology development</span><span lang=EN-ZA><o:p></o:p></span></p><p class=MsoNormal><span lang=EN-ZA style='font-size:14.0pt'>before the release of a well-accepted international testing protocol</span><span lang=EN-ZA><o:p></o:p></span></p><p class=MsoNormal><span lang=EN-ZA style='font-size:14.0pt'> </span><span lang=EN-ZA><o:p></o:p></span></p><p class=MsoNormal><span lang=EN-ZA style='font-size:14.0pt'> </span><span lang=EN-ZA><o:p></o:p></span></p><p class=MsoNormal><span lang=EN-ZA style='font-size:14.0pt'>---------------------------<br></span><span lang=EN-ZA>Kirk R. Smith, MPH, PhD<br>Professor of Global Environmental Health<o:p></o:p></span></p><p class=MsoNormal style='margin-bottom:12.0pt'><span lang=EN-ZA>Chair, Graduate Group in Environmental Health Sciences<br>Director of the Global Health and Environment Program<br>School of Public Health<br>747 University Hall<br>University of California<br>Berkeley, California, 94720-7360<br>phone 1-510-643-0793; fax 642-5815<br><a href="mailto:krksmith@berkeley.edu">krksmith@berkeley.edu</a><br><a href="http://www.kirkrsmith.org/">http://www.kirkrsmith.org/</a><br><br><o:p></o:p></span></p></blockquote><p class=MsoNormal><span lang=EN-ZA style='font-size:12.0pt;font-family:"Times New Roman",serif'><o:p> </o:p></span></p></div></body></html>