class: center, middle, inverse, title-slide # Using Chlorophyll <em>a</em> as a surrogate for exceeding Microcystin Health Advisory Concentrations ## Cyanobacteria - Monitoring and Treating Drinking Water: A Workshop for Water Suppliers ### Jeff Hollister and Betty Kreakie ### <div style="white-space: pre-line;">2017-12-14 Worcester, MA</div> --- class: center, middle, inverse # Problem: What is a bloom? --- # Problem: What is a bloom? ## So of course, I asked Twitter  --- # Problem: What is a bloom? ## Got some of this variety   --- # Problem: What is a bloom? ## Got some of the more quantitative  --- # Problem: What is a bloom? ## And then the one closest to reality  --- # Problem: What is a bloom? ## Take away message .left-column[ - No real consensus - Different definitions - Visual cues - Public concern - Health risk - Still left with a decision on how to quantify ] .right-column[ <img src="scouting_bloom.jpg" style="width: 70%; height: 70%; margin-left: 70px; margin-top: -50px;"></img> ] --- # Problem: What is a bloom? ## What could we use? .left-column[ - Toxins - Most direct measure - Data not widely available - Cell counts, bio-volume, etc. - Data not widely available - Chlorophyll - Data available - Associated with cyanobacteria? ] .right-column[ <img src="yawgoo_fall.jpg" style="width: 80%; height: 80%;"></img> ] --- class: center, middle, inverse # Possible Solution: Chlorophyll as a proxy for Microcystin --- # Possible Solution: Chlorphyll as a proxy .left-column[ - 2007 NLA show association - Yuan *et al* (2014). Freshwater Biology - But, what is a bloom? ] .right-column[ <img src="hollister_kreakie_fig2.gif" style="margin-top: 80px; width: 90%; height: 90%;"></img> .image-credit[Hollister and Kreakie. (2016). https://f1000research.com/articles/5-151/v2] ] --- # Possible Solution: Chlorphyll as a proxy ## Exsiting Microcystin Advisory Levels <table> <thead> <tr> <th style="text-align:left;"> Source </th> <th style="text-align:left;"> Type </th> <th style="text-align:left;"> Concentration </th> </tr> </thead> <tbody> <tr> <td style="text-align:left;"> USEPA </td> <td style="text-align:left;"> Infant and Pre-school Child Drinking Water Advisory </td> <td style="text-align:left;"> 0.3 µg/L </td> </tr> <tr> <td style="text-align:left;"> WHO </td> <td style="text-align:left;"> Drinking Water </td> <td style="text-align:left;"> 1 µg/L </td> </tr> <tr> <td style="text-align:left;"> USEPA </td> <td style="text-align:left;"> School Age Child and Adult Drinking Water Advisory </td> <td style="text-align:left;"> 1.6 µg/L </td> </tr> <tr> <td style="text-align:left;"> WHO </td> <td style="text-align:left;"> Recreational: Low Prob. of Effect </td> <td style="text-align:left;"> 2-4 µg/L </td> </tr> <tr> <td style="text-align:left;"> WHO </td> <td style="text-align:left;"> Recreational: Moderate Prob. of Effect </td> <td style="text-align:left;"> 10-20 µg/L </td> </tr> <tr> <td style="text-align:left;"> WHO </td> <td style="text-align:left;"> Recreational: High Prob. of Effect </td> <td style="text-align:left;"> 20-2000 µg/L </td> </tr> <tr> <td style="text-align:left;"> WHO </td> <td style="text-align:left;"> Recreational: Very High Prob. of Effect </td> <td style="text-align:left;"> &gt;2000 µg/L </td> </tr> </tbody> </table> --- class: center, middle, inverse # Our Solution: Chlorophyll and Microcystin --- # Our Solution: Chlorophyll and Microsystin ## Assocating chlorohpyll *a* concentration with Microcystin guidance levels - Hollister and Kreakie (2016) Associations between chlorophyll a and various microcystin health advisory concentrations. <https://f1000research.com/articles/5-151/v2> - Conditional probability - Probability of one event happening, given another has already happened - Our approach based entirely on data - History in environmental applications - Data - 2007 NLA - EPA and WHO guidance levels --- # Results: Chlorophyll *a* and Microsystin .center[ <img src="hollister_kreakie_fig1.jpg" style="width: 70%; height: 70%";></img> ] --- # Results: Chlorophyll *a* and Microsystin ## Results <table> <thead> <tr> <th style="text-align:right;"> Cond. Probability </th> <th style="text-align:right;"> USEPA Child (0.3 µg/L) </th> <th style="text-align:right;"> WHO Drink (1 µg/L) </th> <th style="text-align:right;"> USEPA Adult (1.6 µg/L) </th> <th style="text-align:right;"> WHO Recreational (2 µg/L) </th> </tr> </thead> <tbody> <tr> <td style="text-align:right;"> 0.1 </td> <td style="text-align:right;"> 0 </td> <td style="text-align:right;"> 0 </td> <td style="text-align:right;"> 0 </td> <td style="text-align:right;"> 1 </td> </tr> <tr> <td style="text-align:right;"> 0.2 </td> <td style="text-align:right;"> 0 </td> <td style="text-align:right;"> 4 </td> <td style="text-align:right;"> 11 </td> <td style="text-align:right;"> 19 </td> </tr> <tr> <td style="text-align:right;"> 0.3 </td> <td style="text-align:right;"> 3 </td> <td style="text-align:right;"> 17 </td> <td style="text-align:right;"> 30 </td> <td style="text-align:right;"> 50 </td> </tr> <tr> <td style="text-align:right;"> 0.4 </td> <td style="text-align:right;"> 11 </td> <td style="text-align:right;"> 37 </td> <td style="text-align:right;"> 66 </td> <td style="text-align:right;"> 80 </td> </tr> <tr> <td style="text-align:right;"> 0.5 </td> <td style="text-align:right;"> 23 </td> <td style="text-align:right;"> 68 </td> <td style="text-align:right;"> 83 </td> <td style="text-align:right;"> 110 </td> </tr> <tr> <td style="text-align:right;"> 0.6 </td> <td style="text-align:right;"> 39 </td> <td style="text-align:right;"> 97 </td> <td style="text-align:right;"> 113 </td> <td style="text-align:right;"> 185 </td> </tr> <tr> <td style="text-align:right;"> 0.7 </td> <td style="text-align:right;"> 66 </td> <td style="text-align:right;"> 126 </td> <td style="text-align:right;"> 256 </td> <td style="text-align:right;"> 871 </td> </tr> <tr> <td style="text-align:right;"> 0.8 </td> <td style="text-align:right;"> 116 </td> <td style="text-align:right;"> 271 </td> <td style="text-align:right;"> 871 </td> <td style="text-align:right;"> 871 </td> </tr> <tr> <td style="text-align:right;"> 0.9 </td> <td style="text-align:right;"> 170 </td> <td style="text-align:right;"> 516 </td> <td style="text-align:right;"> 871 </td> <td style="text-align:right;"> 871 </td> </tr> </tbody> </table> --- # Our Solution: Chlorophyll *a* and Microsystin ## Validation with 2012 National Lakes Assessment - EPA Infant and pre-school children - 50% Cond. Prob. (23 µg/L Chl *a* - 0.3 µg/L Microcystin) - Total Accuracy: 79% - False Negative: 6% <!-- - EPA Infant and pre-school children - 40% Cond. Prob. (11 µg/L Chl *a* - 0.3 µg/L Microcystin) - Total Accuracy: 68% - False Negative: 4% --> .center[ #### Infant and Pre-school - 50% Cond. Prob. <table> <thead> <tr> <th style="text-align:left;"> </th> <th style="text-align:right;"> FALSE </th> <th style="text-align:right;"> TRUE </th> </tr> </thead> <tbody> <tr> <td style="text-align:left;"> FALSE </td> <td style="text-align:right;"> 833 </td> <td style="text-align:right;"> 77 </td> </tr> <tr> <td style="text-align:left;"> TRUE </td> <td style="text-align:right;"> 176 </td> <td style="text-align:right;"> 134 </td> </tr> </tbody> </table> ] <!-- .right-column-even[ #### Infant and Pre-school - 40% Cond. Prob. <table> <thead> <tr> <th style="text-align:left;"> </th> <th style="text-align:right;"> FALSE </th> <th style="text-align:right;"> TRUE </th> </tr> </thead> <tbody> <tr> <td style="text-align:left;"> FALSE </td> <td style="text-align:right;"> 669 </td> <td style="text-align:right;"> 45 </td> </tr> <tr> <td style="text-align:left;"> TRUE </td> <td style="text-align:right;"> 340 </td> <td style="text-align:right;"> 166 </td> </tr> </tbody> </table> ] --> --- class: center, middle, inverse # Applications and Caveats --- # Applications and caveats - Identify potential past bloom events - Screening tool - Helps with limited resources - Test for microcystin only when more likely to find it - Caveat: Current numbers based on National data - Caveat: Analyzing for toxins, if possible, still better - Chlorophyll *a* cutoff to use is management decision .center[ <img src="yawgoo_fall2.jpg" style="width:60%; height:60%;"></img> ] --- # Thanks! .left-column-even[ ## Jeff Hollister US EPA </br> Atlantic Ecology Division </br> Narragansett, RI </br> <i class="fa fa-envelope "></i>: [hollister.jeff@epa.gov](mailto:hollister.jeff@epa.gov) </br> <i class="fa fa-twitter "></i>: [jhollist](https://twitter.com/jhollist) </br> <i class="fa fa-github "></i>: [jhollist](https://github.com/jhollist) </br> ] .right-column-even[ ## Betty Kreakie US EPA </br> Atlantic Ecology Division </br> Narragansett, RI </br> <i class="fa fa-envelope "></i>: [kreakie.betty@epa.gov](mailto:kreakie.betty@epa.gov) </br> <i class="fa fa-github "></i>: [BKreakie](https://github.com/BKreakie) </br> ]