Final answer:
When assigned an environmental audit, the internal audit activity's first step is to review the environmental management system before moving on to compliance checks, risk assessments, or staff training.
Step-by-step explanation:
If the internal audit activity is assigned the responsibility of conducting an environmental audit, the first action that should be performed is to review the environmental management system. Before conducting any compliance reviews of organizational policies and procedures, or providing technical training to staff, it is essential to thoroughly understand the environmental management system that is in place. This initial step lays the groundwork for a systematic approach to the audit by establishing a baseline of operation standards and expected practices which the internal audit will assess for adequacy and efficacy.
Moreover, reviewing the environmental management system will help to identify any gaps or deficiencies that may exist, providing direction for a more targeted compliance check and risk assessment. Only after this review can the auditing team effectively conduct risk assessments for each site (option D) and verify compliance with organizational policies and procedures (option B). Additionally, understanding the system will guide the technical training needs for the staff (option C), ensuring that they have the proper knowledge and skills to conduct the environmental audit effectively. Therefore, in conclusion, the first action that should be performed is option A: Review the environmental management system.