\documentclass[review]{elsarticle}
\usepackage{lineno,hyperref}
\usepackage{pdflscape}
\usepackage{caption}
\usepackage[singlelinecheck=off]{caption}
\usepackage{longtable}
\usepackage{booktabs}
\usepackage{pdflscape}
\usepackage[margin=2.5cm]{geometry}
\usepackage{natbib}
%Import the natbib package and sets a bibliography and citation styles
\bibliographystyle{agsm}
\setcitestyle{authoryear,open={(},close={)}}
\begin{document}
provide safe and hygienic environment to worker
\citep{davim2007turning},
\section*{References}
\bibliography{file}
\bibliographystyle{sample}
\end{document}
The reference is given in the image, where there is normal formatted "et al.", I need it in italic form.

bibliographystylestatements in your example. Does that work? – Johannes_B Apr 12 '17 at 05:10