Is there any factual basis to pork being "dirty" compared to other meats?

This is bullshit. Peoples who do keep pigs feed them on waste, or on things humans only eat in utter desperation, like acorns. They’re not rooting around in the wheat fields. The neighbours of the Jews and later the Muslims had no problem keeping pigs in the same regions - hell, there were herds of swine 2000 strong in Gerasene for Jesus to drive demons into.

No peoples who herd goats can point any fingers at pig farmers in terms of ecological damage. There’s nothing like a goat for turning marginal land into desert.

All I’m hearing is “bacon-fed bacon”

It was.

I know that Marvin Harris has his detractors, but in “The Sacred Cow and the Abominable Pig” he describes a group of North African Muslims who live in a forested area with plenty of tree nuts for pigs forage. This group, while nominally halal, will eat these pigs. Sorry don’t have the book handy for a more exact cite. Harris, as was his way, took this as evidence that food taboos are essentially based on a rational reaction to how to best feed humans based on environmental conditions.

Don’t sweat it. You’re cool

I’m a big fan of Harris, and I think he’s pretty much correct on this issue (and many others). His argument is essentially that what people eat is determined by practical considerations, a sort of “food economics”, and that the reasons given are often rationalizations after the fact.
The eating of pig wasn’t only proscribed by Muslims and Jews, but has much deeper roots, going back to the ancient Sumerians and Egyptians. Wikipedia lists several other places ( Religious restrictions on the consumption of pork - Wikipedia ) .

Harris’ explanation has nothing to do with trichinosis, observing that it is easy enough to prevent illness simply by cooking meat long enough. The real issue, according to him, is that pigs compete with people for food sources, and that it’s more cost-effective to eat most of the things pigs forage for directly (and, presumably, to throw less out as garbage). Cows and sheep and camels eat grass, which people can’t digest. The implication is that among subsistence people, those that don’t waste energy and foodstuff raising pigs are likely to survive more often. The taboo remained even after people were in a better position with respect to food stores.

Historically, pigs and dogs have been poor peoples’ meat- they breed and grow fast, they’re hardy and adaptable, and they can be fed on the scraps humans can’t eat, or turned out to fend for themselves. Cattle and sheep, on the other hand, require grassland-real estate-and large amounts of fodder, which require a certain affluence, making them inaccessible to poor people for the most part. Might not the ill-favor borne by pork and dogmeat have a classist aspect of poverty-scorning?

As previously pointed out, restrictions on pork are very rare except in traditions that originated in the Middle East. Does he explain why the taboo was essentially limited to that area? Why didn’t subsistence farmers elsewhere, such in China or Europe or Papua New Guinea or the Pacific Islands develop this taboo?

To be convincing, an economic explanation for a food taboo has to explain both the instances where a food taboo exists, and those where it doesn’t. Globally, a pork taboo is the exception rather than the rule. I’d be willing to accept it as something that developed in the special conditions of nomadic pastoralism in the arid Middle East and then became a marker of religious and cultural identity, but it’s not a general explanation.

The economic explanation also fails with regard to why camels are not considered kosher. Here we have a perfectly edible animal that doesn’t compete for food with humans, and can survive on forage and less water than is needed by other domestic animals. Why was camel meat forbidden to Jews?

Hunters baiting bear in MN are forbidden to use of any part of a Swine except Cured Pork. and that goes back a long time.
https://files.dnr.state.mn.us/recreation/hunting/bear/bear_regulations.pdf

Back when i was in the Army the scraps from the Mess Hall went int the edible garbage cans to feed pigs at local farms.

Pigs eat garbage, but that’s not why Jews consider them unclean.

The ancient Hebrews were herders, who kept sheep and goats. Other people in the area were farmers, who kept pigs.

When setting up the rules for Kosher, they made them to include the animals they raised (and sacrificed to God) and exclude what other tribes ate to separate them.

Ancient Hebrews weren’t farmers? What did they make their matzoh out of?

At a complete guess, I would say because camels were an important beast of burden, and if they were on the menu, you may end up with a situation where you don’t have enough camels to do all the camel things you need done anymore.

Yes, but camels are regarded as halal in Islam and may be eaten. They were probably far more important for riding and as beasts of burden to the Arabs than they would have been to the early Hebrews.

If I had to guess, it would be because camels were domesticated much later than cattle, sheep, and goats, so they may not have been an important source of food when the Jewish dietary laws were formulated.

Pork is the only meat categorically declared forbidden in Islam, although other kinds of meats such as horse, donkey, carnivores, and others may also be excluded on various grounds. Camels are the only major domestic animal that Muslims may eat but Jews may not.

I assume you’re joking, but they didn’t always have matzohs.

They had bread. Who grew the grain?

The farmers.

The early Hebrews are generally assumed to have been seminomadic pastoralists. Although legendary, Biblical accounts of the patriarchs strongly suggest this (e.g. Abraham and Lot are described as having large herds.) Now, the Bible does also refer to agriculture being practiced, and the Hebrews may have done so in certain times and places. However, from here:

The Middle East is where things like wheat and barley grow wild, and where they were used as wild foods prior to their domestication. There may have been extensive harvesting and storage of fields of wild grain before the invention of deliberate agriculture.

Also, as noted, trade with farmers was also and option once agriculture got going.

This is what I believe most plausible.

I also agree with the bolded. I bet the authors of the bible weren’t really familiar with camels.

There are modern pastoralists, for example in Mongolia. They trade with farmers for bread and other farm goods.