  We give a simple argument showing that the number of edges in the
intersection graph $G$ of a family of $n$ sets in the plane with a linear
union-complexity is $O(\omega(G)n)$. In particular, we prove $\chi(G)\leq
\text{col}(G)< 19\omega(G)$ for intersection graph $G$ of a family of
pseudo-discs, which improves a previous bound.
