Immigration and poison use in cities

Immigrants in New York City are using a toxic chemical in a concentration almost 61 times higher than federal regulations allow to get rid of rats. The product is highly dangerous to humans, and poses a threat in such a densely populated urban center.

The NY Times has published a politically incorrect piece about immigrant purchase and use of poisons in big cities. Typically living at high density and facing a rodent problem, some immigrants turn to purchasing powerful poisons to solve their problem. These products (made in China) promise to leave the "cat unemployed". (This quote made me wonder whether cats are counted in the BLS unemployment statistics?).
In the quote, I reproduce below, the NY Times claims that social networks among immigrants is the reason for the "poison externality". This is an interesting twist on the usual beneficial social networks story that immigrants arrive and learn and succeed and then tell their friends at the origin about the benefits of moving to a location and this creates path-dependent migration.

"The product at the center of that investigation, which government officials disclosed this week, was sold in a box printed with Chinese characters and an awkward English translation: “The Cat Be Unemployed.” Officials said the substance contained a toxic chemical in a concentration almost 61 times higher than federal regulations allowed.
Though several professional exterminators said they had never encountered the product, they said it was just the latest in a stream of goods that for years had flowed from overseas factories into the supply closets of households and businesses in New York.
City health officials said that since 2005 they had received about 100 reports of poisoning from Tres Pasitos and two other anti-pest products favored by immigrants, Tempo and Chinese Chalk. While there were no deaths, about 40 percent of the victims had to be treated in medical centers, officials said.
Lower prices and language barriers can steer immigrants toward the underground market, immigrant advocates say. So can cultural biases: immigrants become familiar with products in their homeland and import their preferences, and sometimes the substance itself, when they move to the United States. They pass along their knowledge and techniques to neighbors and friends. "

So, how should this problem be solved? Could educating the community about the consequences of using this product do the trick? I doubt it because each user will view himself as small. Could rising incomes solve the problem? Perhaps but enforcement will be needed to curb this density externality.
UPDATE: Given that the theme of this blog post is politically incorrect, permit me to continue. There is a long tradition of discussing environmental justice issues in immigrant and minority communities. I have written on this topic. But, in this case --- the concentration of immigrants is causing the pollution challenge.