Graduate Certificate, Diploma or Masters?

[Niagara1111]

Hello Everyone your response will be appreciated.

I have a bachelors in Biology from Nigeria, a masters in environmental engineering from China, I am currently a PR in Canada and I want to move into the environmental health and safety area/ career path. My question is which is the best way to go?
1. Graduate certificate in environmental health and safety (One year)
2. Diploma in Occupational health and safety (Two Years)
3. Masters in occupational and environmental health (Two years)
4. Safety trainings

Please advice and give reasons


Thank you