has it ever interacted with humans?
Yes, Crustaceans such as crabs, lobsters, crayfish, shrimp, and prawns have long been part of human cuisine, and are now raised commercially.
Arthropod
Crustaceans such as crabs, lobsters, crayfish, shrimp, and prawns have long been part of human cuisine, and are now raised commercially. 
does a leech bite? Yes are there bites venomous or poisonous? UNANSWERABLE what is its scientific name? Hirudinea from where does the name originate? UNANSWERABLE is there any correlation between leech and pollution? Exposure to synthetic estrogen from municipal wastewater, can affect leeches' reproductive systems what kind of cultural reference does it have in human society? Horse leech could drive elephants mad by climbing up inside their trunks to drink blood. any specific culture where such references are given? "Natural History" what are some reusable options for the water that affects the leech? It can be reused in industry, in artificial recharge of aquifers, in agriculture and in the rehabilitation of natural ecosystems. name a few pollutants that are biological in nature that is associated with such water? human feces,  non-pathogenic bacteria and animals such as insects, arthropods and small fish. where does the second animal get its name from? It comes from the Greek "árthron" and "pous".
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Arthropod [SEP] Interaction with humans
Crustaceans such as crabs, lobsters, crayfish, shrimp, and prawns have long been part of human cuisine, and are now raised commercially. Insects and their grubs are at least as nutritious as meat, and are eaten both raw and cooked in many cultures, though not most European, Hindu, and Islamic cultures. Cooked tarantulas are considered a delicacy in Cambodia, and by the Piaroa Indians of southern Venezuela, after the highly irritant hairs – the spider's main defense system – are removed. Humans also unintentionally eat arthropods in other foods, and food safety regulations lay down acceptable contamination levels for different kinds of food material.