Toxic Elements and Microbiological Content of Food: Evidence from a Case Study in a Brazilian City Heavily Contaminated by Lead and Cadmium

Abstract

Food security has become a major concern of the world population and this is even more prominence in polluted areas. This study aimed to evaluate microbiological and toxic elements content of local food itens from Santo Amaro, Bahia. The determination of lead, cadmium, Escherichia coli (E. coli) and total coliform were carried out in coriander, cassava, okra, chicken muscle/liver, fish muscle and eggs. The population of total coliform and E. coli were estimated by the express count method using plates EC (AOAC 991.14) and accounting of colonies by colony counter. For toxic elements determination samples were digested using HNO 3 and H 2 O 2 following EPA 200.3 using a digester block with cold fingers. The determination of lead and cadmium was performed by inductively coupled plasma optical emission spectrometery (ICP OES). The mean total coliform has ranged from < 1 to 4.5 log CFU g-1. Coriander presented higher mean total coliform (4.5 log CFU g-1) and E. coli was higher than recommended levels. The range of toxic elements revealed higher concentrations of lead in chicken muscle (1.25-11.58 mg kg-1) and cadmium in eggs (0.45-1.06 mg kg-1). Finally, the risk to the inhabitants of Santo Amaro was evident and reinforces the importance of effective actions of local authorities.

Comet assay to evaluate chromosomal changes in chickens (Gallus gallus domesticus) contaminated by lead in a city in Bahia

“…Thus, the population of Santo Amaro could be affected when the food consumed presents bioaccumulative contaminants in the food chain, especially lead (Pb). The results of previous studies conducted by our research group showed that, among the foods (of plant and animal origin) produced in Santo Amaro and most consumed by the population, the highest levels of cadmium and lead were found in samples of chicken (Gallus gallus domesticus) muscle tissue and in the cassava (Manihot esculenta) (Macedo et al, 2016).…”

“…According to Macedo et al (2016), who found high levels of lead in muscle tissue of chickens from Santo Amaro, the possible source of exposure for these animals was the contaminated soil, as well as the eating habits of these birds that scratch and peck at the ground. The association between eating habits and lead levels in the blood of different groups of birds was demonstrated by Garcia-Fernandez et al (1995) where it was revealed that omnivorous species (such as chickens) and scavengers showed higher levels of contamination by this toxic metal when compared to piscivorous and insectivorous birds.…”

“…Although there are several studies on the contamination of biotic and abiotic elements by toxic metals in Santo Amaro (Carvalho et al, 1984;Costa et al, 2019;FUNASA, 2003;Hatje et al, 2006Hatje et al, , 2010Hatje and Andrade, 2009;Macedo et al, 2016;Muñoz Magna et al, 2013;Santos and Anjos, 2022), few tried to demonstrate potential biological effects caused by these contaminants (Batista et al, 2017;Carvalho et al, 1987;Pinheiro et al, 2023). Therefore, the present study aims to analyze possible chromosomal degradations in chickens (Gallus gallus domesticus) reared in an area potentially impacted by heavy metals and its associations with serum lead concentrations.…”

“…One chicken specimen was obtained from four different small local producers of Santo Amaro (Bahia) distributed in different locations of the city. Figure 1 It is estimated that around 500 thousand tons of waste rich in toxic metals, with 1 to 3% lead, were dumped into the environment, dispersing contaminants throughout the city and region (Macedo et al, 2016). This case is widely described in the scientific literature since the first doctoral thesis works (Carvalho, 1978;Reis, 1975;Spínola, 1975), books with comprehensive literature reviews (Fernandes et al, 2012;Ferran, 2007;Oliveira et al, 2018) and scientific papers recognizing addressing studies on the site's contamination history (Andrade and Moraes, 2013;Carvalho et al, 2003Carvalho et al, , 2018Costa et al, 2020;Macedo et al, 2016;Machado et al, 2013;Muñoz Magna et al, 2013, 2014.…”

A baseline survey on food safety hazards in commonly consumed food items in Sri Lanka

“…If good hygiene is not practiced, yoghurt, a dairy product commonly consumed in Sri Lanka, also gets contaminated with spoilage and pathogenic microorganisms. Presence of coliforms usually indicates failures in hygienic practices in food preparation and Escherichia coli indicates faecal contamination leading to possible food safety issues (Macedo et al, 2017). However, microbial quality of yoghurt greatly varies with the brand due to varying degree of best practices followed by the manufacturers.…”