A K Saran
Nowadays people are more health conscious and emphasize that food should not only be nutritionally balanced but also safe for human consumption. Many national and international agencies are working in collaboration to ensure food safety, and in most of the industrialised countries the issue of food safety, quality and environmental concerns are more important than the product price and income changes (FAO, 2009).
Seafood constitutes an important food component for a large section of world population. Sea foods are a cheap source of animal protein which come after meat and poultry animal protein foods. Seafood is an important diet for many people due to their unique nutritional composition. As the world population is growing, the per capita consumption of seafood is also increasing rapidly.
Formaldehyde is one of the most important compounds for use in the industrial applications. The processes in the upper atmosphere contribute up to approximately to 90 per cent of the total formaldehyde in the environment. Formaldehyde is an intermediate in the oxidation as well as of other carbon compounds, in forest fires, automobile exhaust, and tobacco smoke. When produced in the atmosphere by the action of sunlight and oxygen on atmospheric methane and other hydrocarbons, it becomes part of smog.
Formaldehyde has also been detected in stellar space as well. Formaldehyde does not accumulate in the environment, because it is broken down within a few hours by sunlight or by bacteria present in soil or water. Humans metabolise formaldehyde quickly, so it does not accumulate, converting it to formic acid in the body.
In India, every State must have the mechanisms to collect data, information and reviews to provide a comprehensive analysis of the dynamic formaldehyde market, its exposure, its regulation, and effects on human health by the process of implementation the series of standards to regulate formaldehyde for public exposures. The lack of enforcement sometimes may be disastrous.
Although formaldehyde is a natural metabolic product of the human body, high-dose exposure increases the risk of acute poisoning, while prolonged exposure can lead to chronic toxicity and even may generate carcinogenesis in human body.
Many cases have been reported in India as well as abroad of poisoning, allergy, asthma, and pulmonary damage, cancer as a result of formaldehyde exposure from contaminated foods, drinking water, and polluted indoor air. The chemical hazard or chemical contamination in fish may include natural toxicants such as mycotoxins and marine toxin, environmental contaminants such as mercury and lead and naturally occurring substances.
Among the contaminants, attention has been paid to volatile toxic aldehydes such as formaldehyde classified by the International Agency for Research on Cancer (IARC) in the Group 1 as carcinogenic to humans (IARC, 2004).The amounts of formaldehyde formed depend mainly on the quality of fish, capturing time and temperature of storage, and it causes muscle toughening and water loss in fish species, leading to lower acceptability as well as functionality.
The inhalation of formaldehyde gas in even small quantities by fish handlers may cause irritation in eyes, lungs and peripheral skins followed by bronchitis and pneumonia and those who consume internally may suffer more and may be in some cases fatal. Thorough investigations and health monitoring due to exposure of formalin has to be done by the authorities in order to make realistic estimates.
Literature says that formaldehyde is a nearly colourless gas with a pungent, irritating odour even at very low concentrations (below 1 ppm). Its vapours are flammable and explosive. Most formaldehyde exposures occur by inhalation or by skin/eye contact.
Formaldehyde vapour is readily absorbed from the lungs. In cases of acute exposure, formaldehyde will most likely be detected by smell; however, persons who are sensitized to formaldehyde may experience headaches and minor eye and airway irritation at levels below the odour threshold (odour threshold is 0.5 to 1.0 ppm; OSHA PEL is 0.75 ppm). For sensitized persons, odour is not an adequate indicator of formaldehyde’s presence and may not provide reliable warning of hazardous concentrations. Odour adaptation can occur. Low-dose acute exposure can result in headache, rhinitis, and dyspnoea; higher doses may cause severe mucous membrane irritation, burning, and lacrimation, and lower respiratory effects such as bronchitis, pulmonary distress, or pneumonia. Sensitive individuals may experience asthma and dermatitis, even at very low doses.
Formaldehyde vapours are slightly heavier than air and can result in asphyxiation in poorly ventilated, enclosed, or low-lying areas. Children exposed to the same levels of formaldehyde as adults may receive larger doses because they have greater lung surface area: body weight ratios and increased minute volumes: weight ratios. In addition, they may be exposed to higher levels than adults in the same location because of their short stature and the higher levels of formaldehyde found nearer to the ground. Therefore, we can say that there is the permissible exposure limits or short-term exposure limit or immediately dangerous limits to health.
Therefore, it is suggested that a thorough study need to be done to estimate the public exposure of any form (liquid or gas) of formaldehyde to the human body at different environmental settings of the country.
The writer is Senior Principal Scientist at CSIR-National
Institute of Oceanography
