After seeing clips from the documentary Crude, what is the general role a specialist in health behavior and health promotion could serve in this issue, and what task related to environmental health issues in the film could they undertake?

Crude is a 2009 documentary about an Ecuadorian oil pollution crisis allegedly perpetrated by Chevron and Texaco. As a result of the ongoing crisis, a class-action lawsuit was filed against Chevron, which is the documentary's primary focus. While investigating the lawsuit, filmmaker Joe Berlinger uncovered many terrible stories about people suffering from ill health, which they attributed to the pollution.
A specialist in health behavior and health promotion could fill a variety of roles on either side of this issue. As someone on the ground in Ecuador, for example, the health specialist could assess the various factors present in the community and find ways to improve public health in the area. He or she could consult the locals on ways to make themselves healthier or lessen the effects of those harmful factors. The specialist could identify resources to help and advocate for the community if he or she felt there was a serious health hazard committed by Chevron/ Texaco or any other company.
On the other hand, a specialist working for Chevron/ Texaco (or one who assessed the situation and determined they were not at fault) could identify other possible causes for the community's health issues. He or she could testify as an expert to what else could be making people sick. 
In either situation, a specialist could also organize educational programs and train people on healthful living.