* Bread: Wheat, water, yeast, salt

* Lettuce: Soil, water, sunlight, nutrients

* Tomato: Soil, water, sunlight, nutrients

* Cheese: Milk, rennet, salt, bacteria

* Ham: Pork, salt, water, spices

Origins:

* Wheat: United States, Canada, Europe

* Water: Local water source

* Yeast: Commercial yeast producer

* Salt: Ocean or salt mine

* Lettuce: Local farm or grocery store

* Tomato: Local farm or grocery store

* Cheese: Local dairy farm or grocery store

* Ham: Local meat producer or grocery store

* Pork: Local pig farm

* Milk: Local dairy farm

* Rennet: Stomach of a young calf

* Bacteria: Naturally occurring or commercially produced

Transportation:

* Wheat: Shipped by train, truck, or ship

* Water: Local water supply

* Yeast: Shipped by train, truck, or plane

* Salt: Shipped by train, truck, or ship

* Lettuce: Shipped by truck or plane

* Tomato: Shipped by truck or plane

* Cheese: Shipped by truck or plane

* Ham: Shipped by truck or plane

* Pork: Shipped by truck or plane

* Milk: Shipped by truck or plane

* Rennet: Shipped by train, truck, or plane

* Bacteria: Shipped by train, truck, or plane

Processing:

* Wheat: Milled into flour

* Water: Purified and treated

* Yeast: Grown in a controlled environment

* Salt: Mined or evaporated from seawater

* Lettuce: Harvested, washed, and packaged

* Tomato: Harvested, washed, and packaged

* Cheese: Produced from milk, rennet, and bacteria

* Ham: Cured and smoked

* Pork: Raised on a farm, slaughtered, and processed

* Milk: Pasteurized and homogenized

* Rennet: Extracted from the stomach of a young calf

* Bacteria: Grown in a controlled environment

Packaging:

* Bread: Plastic bag

* Lettuce: Plastic bag

* Tomato: Plastic bag

* Cheese: Plastic wrap

* Ham: Plastic wrap

* Pork: Plastic wrap

* Milk: Plastic jug

* Rennet: Glass jar or plastic bottle

* Bacteria: Glass jar or plastic bottle

Waste:

* Bread: Composted or landfilled

* Lettuce: Composted or landfilled

* Tomato: Composted or landfilled

* Cheese: Composted or landfilled

* Ham: Composted or landfilled

* Pork: Composted or landfilled

* Milk: Recycled or landfilled

* Rennet: Recycled or landfilled

* Bacteria: Recycled or landfilled

The global nutrient tracker tells a complex story about the origins, transportation, processing, packaging, and waste of the ingredients in a sandwich. This story highlights the interconnectedness of the global food system and the environmental impacts of food production and consumption.