Please read the following table in HTML format from a webpage and then answer the question in detail according to the table. Each table cell is defined by a <td> and a </td> tag. Each table row starts with a <tr> and ends with a </tr> tag. 'rowspan=m' and 'colspan=n' represents a cell spaning over 'm' rows and 'n' columns.

Webpage title:
Nuclear fission product
Table title:
Health concerns
Table:
<table id='hittask' contenteditable='False'>
<tr> <th colspan=1 rowspan=1 > Isotope </th><th colspan=1 rowspan=1 > Radiation </th><th colspan=1 rowspan=1 > Half-life </th><th colspan=1 rowspan=1 > GI absorption </th><th colspan=1 rowspan=1 > Notes </th></tr>
<tr> <td class="highlighted"  colspan=1 rowspan=1 > Strontium-90/yttrium-90 </td><td colspan=1 rowspan=1 > β </td><td colspan=1 rowspan=1 > 28 years </td><td colspan=1 rowspan=1 > 30% </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td class="highlighted"  colspan=1 rowspan=1 > Cesium-137 </td><td colspan=1 rowspan=1 > β,γ </td><td colspan=1 rowspan=1 > 30 years </td><td colspan=1 rowspan=1 > 100% </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=1 > Promethium-147 </td><td colspan=1 rowspan=1 > β </td><td colspan=1 rowspan=1 > 2.6 years </td><td colspan=1 rowspan=1 > 0.01% </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=1 > Cerium-144 </td><td colspan=1 rowspan=1 > β,γ </td><td colspan=1 rowspan=1 > 285 days </td><td colspan=1 rowspan=1 > 0.01% </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=1 > Ruthenium-106/rhodium-106 </td><td colspan=1 rowspan=1 > β,γ </td><td colspan=1 rowspan=1 > 1.0 years </td><td colspan=1 rowspan=1 > 0.03% </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=1 > Zirconium-95 </td><td colspan=1 rowspan=1 > β,γ </td><td colspan=1 rowspan=1 > 65 days </td><td colspan=1 rowspan=1 > 0.01% </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=1 > Strontium-89 </td><td colspan=1 rowspan=1 > β </td><td colspan=1 rowspan=1 > 51 days </td><td colspan=1 rowspan=1 > 30% </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=1 > Ruthenium-103 </td><td colspan=1 rowspan=1 > β,γ </td><td colspan=1 rowspan=1 > 39.7 days </td><td colspan=1 rowspan=1 > 0.03% </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=1 > Niobium-95 </td><td colspan=1 rowspan=1 > β,γ </td><td colspan=1 rowspan=1 > 35 days </td><td colspan=1 rowspan=1 > 0.01% </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=1 > Cerium-141 </td><td colspan=1 rowspan=1 > β,γ </td><td colspan=1 rowspan=1 > 33 days </td><td colspan=1 rowspan=1 > 0.01% </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=1 > Barium-140/lanthanum-140 </td><td colspan=1 rowspan=1 > β,γ </td><td colspan=1 rowspan=1 > 12.8 days </td><td colspan=1 rowspan=1 > 5% </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=1 > Iodine-131 </td><td colspan=1 rowspan=1 > β,γ </td><td colspan=1 rowspan=1 > 8.05 days </td><td colspan=1 rowspan=1 > 100% </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=1 > Tritium </td><td colspan=1 rowspan=1 > β </td><td colspan=1 rowspan=1 > 13 years </td><td colspan=1 rowspan=1 > 100% </td><td colspan=1 rowspan=1 >  </td></tr>
</table>
Question:
What are the radioactive isotopes of nuclear fission?
Answer:
⁹⁰Sr and ¹³⁷Cs are the radioisotopes.