This was a shock when researching for the harm of tasteless foods sold by supermarkets. The one overriding problem seems to be the arsenic which is found in soils, rocks, and fresh water as the metal leaches into it. United Kingdom scientists were alarmed to find that baby food had a higher percentage of arsenic than in the recommended standard in drinking water. It is found to lead to lower birth weight and child-hood illnesses.
In the USA, however, rice grown in the Southern States takes up the arsenic from the water, and it is found to be more toxic than rice grown in Asia. This element is carcinogenic and with an ever larger number of cancer and other diseases now now than say 75 years ago it came to my attention that it is probably food related.
As diseases like diabetes, liver failure, kidney disease, and cancer is not location specific but is found in remote communities to be just as prevalent there has to be a food connection. With that in mind my thoughts focused on what has changed in recent years, as from GM crops, to make it like this.
Chemical weapons to counteract pests, weeds, and bugs had been used for centuries, with the earliest date around 700 AD and arsenic was the main element in them. Agricultural land was specifically contaminated with it from the use of old chemicals. It was also added to rat and ant poisons, many of which were used around homes. That makes a lot of crops at risk of having it in their seeds.
While these things are known we do not have a reference to how much aerial spraying spread the chemical. In my young days we had hand pumped fly sprays containing DDT that were squirted in the air along with insect killers that no doubt had a link to that product as well. My grandmother died of cancer in 1953, and she was a great user of them.
The spraying of ground around packed vegetables and fruit was another thing that used to occur to counteract cockroaches and other insects from warehouses. Whether this is still practiced has not come up but supermarkets still spray their shops with chemicals overnight for the same reason. Arriving in one that had just opened in the morning took my breath away and that's when the worker explained about the spraying.
People work in that environment and the fruit and vegetables sit uncovered overnight absorbing the chemical, whatever it contains. These toxins are then absorbed by the consumer.
It is toxins that produce free-radicals and alter the cells in the body to change. That is when cancer forms and things like diabetes and so on result. Without we do our own research and grow our own produce there is no way of telling what the food we eat contains. As to the quantities, that's anyone's guess who does not have the ability to do the necessary tests.