respiratory droplets
... that surgical masks provide effective protection against diseases spread by respiratory droplets , but not those spread by airborne transmission?
... that <a href="./Surgical_mask" id="mwCNU" rel="mw:WikiLink" title="Surgical mask">surgical masks</a> provide effective protection against diseases spread by <b id="mwCNY"><a href="./Respiratory_droplet" id="mwCNc" rel="mw:WikiLink" title="Respiratory droplet">respiratory droplets</a></b> <i id="mwCNg">(examples pictured)</i>, but not those spread by <a class="mw-redirect" href="./Airborne_disease" id="mwCNk" rel="mw:WikiLink" title="Airborne disease">airborne transmission</a>?