The prevailing winds in St Maarten are fairly constant and overwhelmingly from the East so it seem to me that pollution probably does not linger over the island for long. That does not mean that cruise ship pollution is not a global problem. These sources all seem to agree that cruise ship are big polluters. Politically, some are right leaning and some are left leaning.

https://www.transportenvironment.org/press/luxury-cruise-giant-emits-10-times-more-air-pollution-sox-all-europe%E2%80%99s-cars-%E2%80%93-study

https://www.forbes.com/sites/jamese...and-environmental-problems/#e3e3a9537db3

https://www.businessinsider.com/cru...l-caribbean-among-worst-polluters-2019-7

https://www.marketwatch.com/story/c...to-pollution-charges-pay-fine-2016-12-01

Jim