I've not been checking this board recently but am glad to see the discussion of that awful smell and putrid air. First, YES, there are negative consequences of this: asthma, allergic rhinitis, exacerbation of COPD (Chronic Obstructive Pulmonary Disease), cardiovascular issues, migraines & other headaches, eye strain & disorders, insomnia, anorexia, LWB babies & premie labor, and generalized nausea. These are well documented in the public health literature when there is an ongoing "bad air" state. In the past, there was a theory of disease called Miasmia or "bad air" which went out of favor. Now we are discovering all of the negative impacts that environmental contaminants can have.
Now, I must say that eliminating the 'pond' is NOT the answer for a number of reasons including the fact that it isn't the main source of the smell. Although the pond area surrounding the bridge into SPM city may look like the cause of the problem, it is not likely to be the cause of THIS problem. Indeed, it breeds mosquitos, which can equate to Dengue Fever and Malaria (pond/lagoon/swamp drainage is a common method of dealing with these but destroys major habitat for wetlands creatures), but I refer you to this for the global benefits of ponds:
Ponds Found To Take Up Carbon Like World's Oceans
IF there is open sewage going into the pond/swamp, then yes, it may fester and become rancid awful smelling (it's the methane). However, that would be a more ubiquitous smell that doesn't come and go. We go in and our of SPM daily and some days the smell is like one is sitting in a rotten egg salad factory with overflowing sewers running through, and other times it is barely noticeable. There IS a correlation between the two main factory stacks that are pumping out pollutants into the air. The sugar cane factory is definitely burning of sulfur and that is where the rotten egg smell comes from. I suspect that there is also some illegal dumping (okay--it WOULD be illegal anywhere else) into the swamp and when the moist humid vapors get blown into JD (nightly at around 7 PM when it is cool enough to open up your house and air it). Thus, I believe this to be a multifactoral problem of burning left over sugar, fermenting & rotting sewage=methane, solid waste disposal, humidity and wind.
When the rains come, we get a BRIEF respite until there is ever so slight a breeze this way and then it is worse. I know that our friends who use AC 24/7 haven't the slightest clue that this problem exists. Most of them go from AC homes to AC cars to AC'd offices or stores. For those of us who don't live this way, this is a serious issue that reminds us every night why buying without living someplace is a bad idea. I feel truly sorry for those who are in that position or where the environment became worse after their purchase.