Using a ‘value’ with spaces?

Dear Custom Content SHortcode,

How do I use a value that has spaces in it?

<ul>[loop type=hboclusters field=cluster_sector value=gezondheid]
<li><a title="[field cluser_naam]" href="[field url]">[field cluser_naam]</a></li>
[/loop]</ul>

this works perfectly!

But this one doesn’t:

<ul>[loop type=hboclusters field=cluster_sector value=aarde en milieu]
<li><a title="[field cluser_naam]" href="[field url]">[field cluser_naam]</a></li>
[/loop]</ul>

Would love to know how to make this work!