Slowly their camps have grown together. The poorest neighborhoods are chaotic, streetless, and so dense that the eye has trouble taking them in. There is no electricity or plumbing. Steep paths wind between the shelters, which are built of scrap plywood, packing crates, car doors, salvaged tin, worn tires, and cardboard. People suffer from malnutrition, disease, parasites.
Rainstorms slicken the hillsides and scour the garbagestrewn gulches.
Down in the valley the Nogales wash runs with sewage and industrial waste. The mixture flows north into Arizona, carrying sickness and poison. Last year it caught fire. For all this, some people blame the maquiladoras. Import codes in both countries allow this to happen almost duty free.