What should be done about dust and dirt on walls that could damage dry-van cargo?

Washing the walls is the most effective action to take regarding dust and dirt accumulated on the walls of a dry-van cargo space. Such contaminants can potentially interfere with the integrity of the cargo being transported. Dust and dirt may introduce moisture or other unwanted substances that could harm sensitive items, particularly those that are perishable or susceptible to contamination.

In this case, simply washing the walls ensures that any dust or dirt is removed and helps maintain a clean environment for the cargo. This preventative maintenance is essential for protecting the cargo from exposure to particles that could lead to spoilage or damage during transportation.

Other options such as using a vacuum cleaner could remove some debris but may not thoroughly cleanse surfaces as effectively as washing, particularly for sticky residues or grime. Painting the walls might actually cover damage or dirt but does not address the underlying issue of contamination. Lastly, taking no action is not advisable, as the presence of dust and dirt can lead to potential cargo damage. Thus, washing the walls stands out as the most comprehensive solution for ensuring a safe transport environment for the cargo.