Vegetable production chain water contamination

Enteric pathogens have to be introduced into the production chain at some point in order to contaminate fresh produce. Direct fecal contamination of vegetables just prior to consumption represents the greatest risk (Gorny, 2002 Mukherjee et al., 2007). However, other sources of contamination such as manure amended soil and irrigation water are more commonly encountered (Hutchison et al., 2008 Islam et al., 2004). 

Indirect effects on people in the commimity whose health and safety can be impaired by a persistent low level loss of contaiimient such as may occur if the contents of an underground storage tank leaks into an aquifer from which drinking water is abstracted. Food safety can be compromised if poor production control permits contaminants to arise. One example was the contamination of Perrier Water by traces of benzene. Indirect effects arise from pesticides used in the food chain. In today s international commercial markets produce arrives on supermarket shelves from around the world. The impact of pesticides used on fruit or vegetables in one part of the world may affect the inhabitants of another continent. 

The food chain is the primary pathway of human exposure to dioxin, with meat (38%) and dairy products (28%) dominating. Fish ingestion can be a significant contributor in countries with high fish consumption (26% of total intake in the Netherlands), but is not an important factor in the US. The exact contribution of fruits and vegetables is unclear, but vegetable oil does appear to play a role in human dioxin exposure. Inhalation and consumption of contaminated water and soil are not major sources of human exposure to TCDD. 

The analytical methods used for the determination of uranium in environmental samples are basically the standard methods reviewed in brief in Chapter 1. The main differences are in the sample preparation procedures required for the analysis of the variety of environmental samples that include soil of different types, sediments, diverse types of vegetation, water from different sources with a wide range of acidity, salinity, suspended matter, etc. In addition, the environmental samples may include airborne particulate matter, vapors, and gases, as well as special samples involved in the food chain that may affect humans. Einally, the interplay of uranium (and other contaminants) between the environmental compartments—for example, the transfer factors of uranium from soil-to-plant or from vegetation to food products (e.g., free-range grazing cattle) are also part of the media that need to be characterized. 

Leaching of BPA built-into polymers is another problem. Unfortunately, the ester bond that links the BPA molecules into polymer chains is not stable. Hence, the polymers degrade in time and release free BPA into materials which come into contact with the BPA-based polymer, for example into the food or water consumed by people and animals. This is why many products manufactured from BPA-derived polymers, particularly the food or drink packages and epoxy can-coated packages for drinks, vegetables or fruits are considered as unsafe and possibly dangerous. Thus, various methods for the BPA detection [112] and analysis in contaminated water and food were developed [113,114]. 

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