Risk Assessment of Chemical Contaminants: Nestle

Speaker: Dr. V. Sudershan Rao, POScientist ‘D’ National Institute of Nutrition


In this video presentation, two major case studies were conducted and the contaminants intake by individuals was analysed (in Rural and Urban settings - Andhra Pradesh). In both the scenarios, there are around 20 plus food items identified that constitute 90 percent of calories ingested. From fluorides, mycotoxins, and pesticides to toxic metals, the consumption is further sub-divided indicating the unintentional daily intake of chemical contaminants by an individual. An equivalent stress is laid upon the consumption of trans-fat and another issue highlighted is that of the milk products adulteration with melamine, which is a growing concern. The final conclusion is that total diet studies have to be conducted at regular intervals.

Key global food safety concerns are microbiological hazards, pesticide residues, misuse of food additives, chemical contaminants, including biological toxins, adulteration, genetically modified organisms, allergens and veterinary drugs residues. Ingestion of excessive amounts of contaminants (such as lead, mercury, arsenic, cadmium, PCBs, dioxins) and other chemicals (such as pesticides) via food supply has harmful effects on consumers health. They also affect all major organs of the body, causing serious health hazards (cancer, births defect and brain damage which are detrimental.

Risk Assessment has the following terms. Hazard Identification is defined as the agents capable of causing adverse health effects. Hazard Characterization is the qualitative and/or quantitative evaluation of the nature of the adverse health effects associated. For chemical agents, a dose-response assessment should be performed. Exposure Assessment is the qualitative and/or quantitative evaluation of exposure via food as well as exposures from other sources if relevant. Risk Characterization is the qualitative and/or quantitative estimation, including attendant uncertainties, of the probability of occurrence and severity of known or potential adverse health effects in a given population.

Regulatory monitoring involves maximum residue limits/tolerance limits for chemical contaminants in individual foods. Effects of processing techniques are not considered while fixing the limits. Total Diet Studies involves measuring the contaminants intake by individual. Samples are processed as per consumption i.e. “table ready”. Results based on analysis of edible portions (not raw). Take into consideration the reduction of those chemicals that degrade during processing at home. If comparisons are done with international reference standards then the intake levels of contaminants ADI’s and PTWI’s is measured for respective contaminants for risk assessment. The mean contaminants levels in the intake calculations appropriate estimate of long term exposure.

Major source of trans-fat is partially hydrogenated fat. There is an increased risk of cardio vascular diseases. There is a need to declare trans-fat on the label. Trans-fat free is the scenario if trans-fat is less than O.2 gram per serving.

Consumer concerns about food safety risks due to chemical contaminants can be addressed by carrying out total diet studies at regular intervals, development of science based standards and a basis for effective risk communication.