fix(plastic-health): update WHO PDF link to IRIS archive, restore ref-18 CAS card

Ultraworked with Sisyphus

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

web/articles/plastic-health.html

@@ -1098,7 +1098,7 @@
     <div class="two-col-grid" style="margin:1.2rem 0;">
       <div class="citation-card" style="margin:0;">
         <div class="source">微塑料过滤</div>
-        <div class="findings">电解还原水机通常内置多层过滤系统（PP棉+活性炭+UF超滤），可有效去除水中微塑料、余氯、重金属等污染物。出水纯净度远超市面桶装水。</div>
+        <div class="findings">电解还原水机通常内置活性炭+精密滤芯过滤系统，可有效去除水中微塑料、余氯、重金属等污染物。加装前置过滤器后形成双重过滤，保护电解板的同时进一步提升出水纯净度。</div>
       </div>
       <div class="citation-card" style="margin:0;border-left:4px solid var(--green);">
         <div class="source">矿物质保留</div>
@@ -1247,7 +1247,7 @@
     <div id="ref-17" class="citation-card">
       <div class="source">[17] 世界卫生组织 (WHO) · 2005</div>
       <div class="findings">Nutrients in Drinking Water. WHO 报告第12章"HEALTH RISKS FROM DRINKING DEMINERALISED WATER"明确指出：长期饮用去矿物质水可能对健康产生负面影响，包括增加矿物质流失、心血管风险和代谢负担。</div>
-      <a class="link" href="https://www.who.int/water_sanitation_health/dwq/nutrientschap12.pdf" target="_blank">🔗 WHO 第12章原文 PDF</a>
+      <a class="link" href="https://iris.who.int/bitstreams/ee809f3c-d909-4138-9242-002bce630853/download" target="_blank">🔗 WHO 第12章原文 PDF (IRIS)</a>
       <a class="ref-link-icon" href="../img/ref-17.png" target="_blank">📷 查看截图</a>
     </div>