Pet food as biosecurity early warning for China

A recent tainted pet food recall has pinned aminopterin as the contaminant.

Aminopterin is used as a rat poison in some countries, but is not registered for that purpose in Canada or the U.S...
The company and investigators at the U.S. Food and Drug Administration had been focusing on wheat gluten, a source of protein in the pet food...
ABC News reported the chemical was on wheat imported from China. Menu Foods has neither confirmed nor denied it uses wheat from China.

Aminopterin prevents the body from using folic acid. Deficiencies in folic acid can lead to neural-tube defects (NTDs) in children. Is China unintentionally poisoning its own? The NTD rate in Northern China is troubling.

Rates of anencephaly in Asia have been reported to be comparable to those of other regions outside the British Isles, while spina bifida prevalence was lower in Asia than elsewhere (Little and Elwood, 1991). However, NTD prevalence in northern China has been reported to be among the highest in the world (Moore et al., 1997).

That's geographically coincident with the major wheat production region in China.

Most of China’s wheat production is in the North China Plain in the central and eastern part of the nation, where three provinces — Henan, Shandong and Hebei — produce more than 50 percent of the national crop.