H1N1 and H3N2 swine flu viruses are endemic among pig populations in the United States and something that the industry deals with routinely. Outbreaks among pigs normally occur in colder weather months (late fall and winter) , but can occur year round. While H1N1 swine viruses have been known to circulate among pig populations since at least 1930, H3N2 influenza viruses did not begin circulating among pigs in the United States until about 1998. The H3N2 viruses initially were introduced into the pig population from humans. However, since then the H3N2 viruses circulating in pigs have changed. The H3N2 viruses circulating in pigs now are very different from the seasonal H3N2 viruses that circulate in humans.
Soylent's website displays the Proposition 65 warning required by California.  Rosa Foods published the position that the levels of heavy metal content in Soylent "are in no way toxic, and Soylent remains completely safe and nutritious".  Rosa Foods also published an infographic and spreadsheet based on an FDA study of heavy metal content in common foods, comparing two selected example meals to servings of Soylent with a similar amount of caloric intake. Both of the company's chosen comparison meals include high levels of cadmium and arsenic , along with levels of lead similar to those of Soylent; although one of them includes tuna and the other includes salmon , providing over 97% of the arsenic in each proposed meal, with spinach providing 74% of the cadmium in the higher-cadmium meal and fruit cocktail providing 71% of the lead in the higher-lead meal.
Biofortification is the process by which the nutritional quality of food crops is improved through agronomic practices, conventional plant breeding, or modern biotechnology. Biofortification differs from conventional fortification in that biofortification aims to increase nutrient levels in crops during plant growth rather than through manual means during processing of the crops. Biofortification may therefore present a way to reach populations where supplementation and conventional fortification activities may be difficult to implement and/or limited.