This study was carried out to evaluate the status of chromium (Cr) concentration in broiler feed and water with risk assessment of chromium (Cr) in broiler meat, liver and brain. Atomic Absorption Spectrophotometer (AAS) was used to determine the chromium (Cr) concentration in feed, water, broilers, liver and brain samples. Therefore, it is suggested that uncertain steps should be taken to detect chromium in poultry feed to assess health risks and to protect humans from foods that may have serious adverse health effects.
General feature
In addition, some heavy metals are non-biodegradable and easily accumulate in the tissues of organisms, causing serious health problems along the food chain (Tchounwou et al., 2013). The risk associated with exposure to heavy metals present in food has raised widespread concern about human health. Improvements in food production and processing technology have increased the possibility of food contamination with various environmental pollutants, especially heavy metals.
Objectives
In terms of density; they are referred to as metals with density (specific gravity) greater than 5 g/cm3 (Lozet and Mathieu, 1991; Morris, 1992). In terms of atomic weight; they are high atomic weight (relative atomic mass) metals (Porteous, 1996; Oxford Dictionary of Sci., 1999). In terms of atomic number; they are metals with atomic numbers greater than 20 (Hale and Margham, 1988) or metals with atomic numbers between 21 (scandium) and 92 (uranium) (Lyman, 1995).
Types of heavy metal
The term heavy metals is widely used as a group name for metals and metalloids that have been associated with contamination and potential toxicity or ecotoxicity. Definition in terms of toxicity; elements commonly used in industry and generally toxic to animals and to aerobic and anaerobic processes, but not all are denser or completely metallic.
Contamination sources of heavy metal
Entry routes
Transport of chromium into the environment
Air contamination
The estimates of 1976 and 1980 atmospheric chromium emissions in the Los Angeles, CA and Houston, TX areas indicate that emissions from stationary fuel combustion are approximately 46-47% of the total, and emissions from the metal industry range from 26 to 45 %. of the total (Agency for Toxic Substances and Disease Registry, 2000). The combustion of coal and oil contributes an estimated 1,723 tons of chromium per year to atmospheric emissions; however, only 0.2% of this chromium is Cr(VI). In contrast, chromium sources contribute an estimated 700 tons of chromium per year to air pollution, 100% of which is believed to be Cr(VI) (Agency for Toxic Substances and Disease Registry, 2000).
Water contamination
Soil contamination
Heavy metals in water
Heavy metal-chromium
- Forms of chromium
- Divalent chromium
- Hexavalent chromium
- Trivalent chromium
- Chromium in poultry
- Health effects
- Mechanisms of toxicity and carcinogenicity
Among them, chicken meat has remained a major source of animal protein in people's daily diet (Salavu et al., 2014. A large proportion of Bangladeshi people consume poultry meat and eggs to meet their protein requirements ( Shahidul et al., 2007) Poultry farming has now become one of the most important agricultural sectors in the world and has rapidly improved as a dynamic industry in Asia (Mahesar et al., 2010).
About 90% of tanning industries use basic chromium sulfate (BCS) during tanning (Aravindhan et al., 2004); this chromium sulfate binds with the collagen protein to stabilize it from degradation. Cr(VI) compounds, which are strong oxidants and therefore tend to be irritants and corrosives, appear to be systemically much more toxic than Cr(III) compounds, given their similar abundance and solubility (Connett et al., 1983). Cr(VI) reduction is considered a detoxification process when it occurs at a distance from the target site for a toxic or genotoxic effect, while Cr(VI) reduction may serve to activate chromium toxicity if it occurs in or near the cell nucleus of target organs (Dayan et al., 2001).
Any of these species can attack DNA, proteins and membrane lipids, thereby disrupting cellular integrity and functions (Mattia et al., 2004). Oxidative damage is considered to be the underlying cause of these genotoxic effects, including chromosomal abnormalities (Goulart et al., 2005) and DNA strand breaks. Nevertheless, recent studies show a biological relevance of non-oxidative mechanisms in Cr (VI) carcinogenesis (Zhitkovich et al., 2001).
It varies greatly among a wide variety of very different Cr (VI) compounds (Katz et al., 1993).
Bioaccumulation of heavy metals
Factors affecting bioaccumulation of heavy metals
Chromium concentration in food sample was found 0.00 in farm A, farm C and farm E respectively (Table-4.1). Table-4.1: Chromium concentration) in different food samples. In the case of meat, the highest average concentration of chromium level was found to be 0.857 mg/kg. In the case of liver, the highest average concentration of chromium level was found to be 2.7003 mg/kg.
In the case of brain, the highest mean concentration of chromium was 3,550 mg/kg. It should be emphasized that chromium, especially Cr (III), plays an important role in the functioning of the body (metabolic functions, cofactor of insulin production, etc.) in trace amounts, but it turns out to be toxic when it exceeds the tolerance. border (Alam et al., 2011). The permissible limit of chromium in meat is 1 mg kg-1. The average chromium level in meat found in this study ranged from 0 to 0.857 mg/kg. The highest Cr concentration was observed in Farm D sample (0.94 mg kg-1) and zero Cr concentration was observed in Farm A, Farm C and Farm E meat sample.
This study reveals that the average concentration of chromium (Cr) in all liver samples was 0 to 2.7 mg/kg, which was higher than the permissible limit. High concentration of chromium in broiler feed resulted in their bioaccumulation in broiler muscle tissue. The higher the chromium in the feed, the higher the accumulation in the different edible organs of the broiler.
It has found that a higher concentration of chromium is bioaccumulated in the brain of broilers apart from the liver, which is higher than the permissible limit, and the accumulation of chromium in broilers is lower than the permissible limit.
Mechanisms of bioaccumulation
Analytical technique used for heavy metal analysis
Atomic Spectroscopy
This technique is applicable to most gas-phase elements over a wide concentration range and involves detecting, measuring and analyzing radiation absorbed or emitted by the atoms or ions of the element of interest (McMahon, 2007). In all of the above, intense heat decomposes the sample into hot gases consisting of free atoms and ions of the element of interest (McMahon, 2007).
Principle of AAS
AAS involves measuring the drop in light intensity from the initial Io radiation to the final I radiation, depending on the metal concentration.
Instrumentation of AAS
In atomization, fuel gases and oxidants are introduced into a mixing chamber which passes through slits in the combustor head. A flame is produced and the sample is aspirated through air into the mixing chamber. The system is flushed with an inert gas to prevent burning of the tube and to exclude air from the sample compartment.
The tube is electrically heated to vaporize the solvent, the sample is then removed and further heated to rapidly vaporize and atomize the sample (Nielsen, 2010). Elemental mercury is then transported in a stream of air or argon to an absorption cell where absorption occurs (Nielsen, 2010). It isolates a single atomic resonance line from the spectrum of lines emitted by the hollow cathode lamp.
The scattering device causes the different wavelengths of light in the source beam to be scattered at different angles. Prisms have limitations, their resolution is significantly lower than the grating system and their separation technique is non-linear which creates mechanical problems with focusing a specific wavelength in the output slit. The tilt angle of the grating device determines the wavelength band that exits the monochromator and reaches the detector.
The selection of the study area depends on the purpose of the study, the ease of collecting and analyzing the sample.
Study period
Study design
Sample collection
Number of samples
Diagnostic evaluation
Processing of samples
The filtrate sample was taken in felcon tubes from the standard volumetric flask and the samples were then analyzed through Atomic Absorption spectrometer. Then 65% nitric acid (HNO3) was added drop by drop until the PH of the water reached 2. Then the water sample was transferred to volumetric flask and heated to 80-90℃ until the water became clear.
Standard preparation
Detection and estimation
Statistical analysis
Concentration of the element by AAS (ppm) ×Volume made up/sample weight In case of feed, the highest average concentration of chromium level was found 3.510 mg/kg. In the present study it was revealed that in case of water concentration of chromium was found 0.00 mg/l in all farm (Table-4.5). In this study, in the case of farm A, farm C farm D and farm E, correlation coefficient of chromium in feed and liver was strongly positive, but farm B was strongly negative.
The present study was conducted to investigate the presence of chromium level in broiler feeds and meat from selected farms of Chattogram City, Bangladesh. In the regulations of EU (2003) there are no maximum permitted concentrations of chromium for feed ingredients and compound feed. This study found chromium in some of the broiler meat samples, but lower than the permissible limit.
The maximum concentration of Cr was observed in the sample of farm D and the minimum concentration of Cr was observed in the brain sample of farm A, farm C and farm E. The alarming news is that some studies found that the meat of birds and other organs of edibles are possessed with significant amounts of chromium, which has a very toxic and carcinogenic effect on the human body for long-term consumption above the permitted limit. The result of this study shows that broilers raised on commercial feed have significant concentrations of chromium above the permitted levels of FAO/WHO.
Recovery of chromium from the tannery wastewater using Bacillus subtilis in Gujranwala, Pakistan. Risk assessment of chromium levels in broiler feeds and meat from selected farms of Bangladesh. Detection of chromium (Cr) using X-ray fluorescence technique and investigation of Cr propagation from poultry feed to egg and chicken meat.
