Very pertinent question , but I doubt anyone has carried out any research on this issue. It will be very interesting to see some  informative responses on this issue .

we worked on the issue of depleted uranium (DU) https://idw-online.de/de/news124118

lokk in my portfolio, there is more to read about this projects!

Learning German opens you a treasure of information:

http://www.strahlentelex.de/Uranmunition.htm,

http://www.bits.de/public/articles/ami/ami5-03.htm

Lead shot being a reason for lead poisoning of animals ( e.g grazing cows) has been addressed in the past.

Thanks dear colleagues, let other talk too on this important but neglected topic.

The question is a very deep one. As at now I don't think anyone has carried out a research on that, but i do know that most of the freshwater systems in the world are getting polluted day in day out. With freshwater constituting less than 3% of the water in the world and more than 1% of that existing in solid (ice) form, burning of ammunition will certainly have a toll on freshwater since that is what farmers depend on in agriculture. Burning of ammunition leaves traces of poisonous and radioactive elements such as uranium  in the earth crust. Ultimately, when it rains, two negative things happen. There is streamflow into rivers, lakes and other water bodies on which agriculturists depend on for irrigation purposes. This deteriorates the soil structure and affects the growth of plants. Secondly, some of these elements are leached and this can also affect groundwater. However, this is less serious as sometimes groundwater is too deep to be reached.

The Middle East has the highest concentration of wars in the world, therefore most of the water bodies in the countries that engage in wars have their freshwater systems degraded. Apart from that, livestock are also destroyed. All this have a toll on agriculture and since burning of ammunition is frequent in such places, the contamination is also drastic.

I understand surely there are many environmental risks associated with burning war ammunition, particularly middle east areas. The scientists of these countries and else where Fire Ranges (where ammunition is tested) some work has to be initiated. Some ENGO with the cooperation of local institutions or government agencies may take the lead.

This might be interesting for the discussion:

https://www.researchgate.net/publication/279754497_Chemical_stabilisation_of_lead_in_shooting_range_soils_with_phosphate_and_magnesium_oxide_Synchrotron_investigation

Article Chemical stabilisation of lead in shooting range soils with ...

Thanks Dr. Ewald Schnug for providing useful link to readers.