Kg-1 Bw Day-1 Research Articles

Safety evaluation of organochlorine pesticides and polybrominated diphenyl ethers in imported canned fish in Nigeria

Organochlorine pesticide (OCP) and polybrominated diphenyl ether (PBDE) concentrations were measured in thirty popular brands of imported canned fish (mackerel, sardines, and tuna) in Nigeria to ascertain potential threats to humans arising from their consumption. The Σ20 OCP concentrations in mackerel ranged from 0.47 to 7.36 ng g−1, while those of tuna and sardines varied from 1.06 to 2.19 and 0.11 to 12.7 ng g−1, respectively. The Σ39 PBDE concentrations in mackerel varied from 0.06 to 4.21 ng g−1, while those of tuna and sardines ranged from 0.19 to 3.18 and 0.04 to 8.26 ng g−1, respectively. The estimated daily intake (EDI) of OCPs and PBDEs from ingestion of the canned fish by adults and children were in the magnitude of 0.03 to 17.6 ng kg−1 bw day−1 and 9.9 × 10−3 to 11.5 ng kg−1 bw day−1 respectively. The hazard index (HI) and total cancer risk (TCR) values for OCPs and PBDEs from ingestion of the canned fish were less than 1 and 10−6, respectively. The dietary intakes of OCPs and PBDEs from these brands of canned fish by adults and children result in no adverse non-cancer and cancer risks.

Remarkable Contamination of Short- and Medium-Chain Chlorinated Paraffins in Free-Range Chicken Eggs from Rural Tibetan Plateau.

Rapid social-economic development introduces modern lifestyles into rural areas, not only bringing numerous modern products but also new pollutants, such as chlorinated paraffins (CPs). The rural Tibetan Plateau has limited industrial activities and is a unique place to investigate this issue. Herein we collected 90 free-range chicken egg pool samples across the rural Tibetan Plateau to evaluate the pollution status of CPs. Meanwhile, CPs in related soils, free-range chicken eggs from Jiangxi, and farmed eggs from markets were also analyzed. The median concentrations of SCCPs (159 ng g-1 wet weight (ww)) and MCCPs (1390 ng g-1 ww) in Tibetan free-range chicken eggs were comparable to those from Jiangxi (259 and 938 ng g-1 ww) and significantly higher than those in farmed eggs (22.0 and 81.7 ng g-1 ww). In the rural Tibetan Plateau, the median EDI of CPs via egg consumption by adults and children were estimated to be 81.6 and 220.2 ng kg-1 bw day-1 for SCCPs and 483.4 and 1291 ng kg-1 bw day-1 for MCCPs, respectively. MCCPs might pose potential health risks for both adults and children in the worst scenario. Our study demonstrates that new pollutants should not be ignored and need further attention in remote rural areas.

Polybrominated Diphenyl Ethers in Human Milk of Croatian First-Time Mothers: 2010 Versus 2020.

The presence of selected polybrominated diphenyl ethers (BDE-28, -47, -99, -100, -153, -154, and -183) was investigated in human milk samples collected from first-time mothers living in Zagreb, capital of Croatia. Samples from 2020 and 2010 were analyzed, and the first temporal comparison between the profiles and levels of these compounds in this area was obtained. A statistically significant difference between mass fractions depending on the sampling year was observed only for BDE-99, with values in 2020 higher than in 2010. BDE-153, whose median value (0.25 and 0.26ngg-1 lipid weight (l.w.) in 2010 and 2020, respectively) did not decrease in the 10-year period, was the most frequently detected congener in samples from both years. ΣPBDEs ranged from < LOD to 3.53ngg-1l.w. (median 0.25ngg-1l.w.), and from 0.14 to 6.75ngg-1l.w. (median 0.55ngg-1l.w.) in 2010 and 2020, respectively. Maternal age and reported fish consumption had no effect on observed PBDE mass fractions, while for BDE-153, positive significant correlation (p > 0.05) was observed of its detected mass fraction with mother's body mass index (BMI) before pregnancy and after childbirth. Infants median estimated daily intake (EDI) via milk ingestion for ΣPBDE was higher in 2020 (3.221 ng kg-1 bw day-1) compared to 2010 (1.429ngkg-1bwday-1), but both values were well below threshold value, indicating that human milk consumption in this specific case is unlikely to raise health risks to infants.

Deoxynivalenol Exposure Induced Colon Damage in Mice Independent of the Gut Microbiota.

To investigate whether deoxynivalenol (DON) can induce intestinal damage through gut microbiota in mice. Mice are orally administered DON (1 mgkg-1 bwday-1 ) for 4 weeks, and then recipient mice receive fecal microbiota transplantation (FMT) from DON-exposed mice after antibiotic treatment. Furthermore, the mice are orally treated with DON (1 mg kg-1 bwday-1 ) for 4 weeks after antibiotic treatment. Histological damage, disruption of tight junction protein expression, and increased oxidative stress and apoptosis in the colon as well as higher serum lipopolysaccharides are observed after DON exposure. Moreover, DON exposure changes the composition and diversity of the gut microbiota as well as the contents of fecal metabolites (mainly bile acids). Differential metabolic pathways may be related to mitochondrial metabolism, apoptosis, and inflammation following DON exposure. However, only a decrease in mRNA levels of occludin and claudin-3 is observed in the colon of recipient mice after FMT. After depleting the gut microbiota in mice, DON exposure can also cause histological damage, disorders of tight junction protein expression, and increased oxidative stress and apoptosis in the colon. DON exposure can induce colon damage in mice independent of the gut microbiota.

Second order probabilistic assessment of chronic dietary exposure to aflatoxin M1 in Serbia.

Considering the genotoxic and cancerogenic nature of aflatoxin M1 (AFM1), its presence in milk and dairy products may pose health risks for consumers. The chronic exposure was calculated using a two-dimensional (second order) Monte Carlo model. Results of 13 722 milk and dairy product samples analysed in the 2015-2022 period were used. Milk and dairy products intake information was collected with a Food Frequency Questionnaire (FFQ) validated by a 24-h recall-based method. Risk characterization was done by calculation of the Margin of Exposure (MOE) and by calculation of AFM1 induced number of hepatocellular carcinoma (HCC) cases. Mean AFM1 Estimated Daily Intake (EDI) was highest in children at 0.336 (CI: 0.294-0.385) ng kg-1 bw day-1, followed by adolescents with 0.183 (CI: 0.164-0.204), then adult females with 0.161 (CI: 0.146-0.179) and finally adult males with lowest EDI of 0.126 (CI: 0.115-0.139) ng kg-1 bw day-1. MOE values based on mean EDI for all population groups were above risk associated threshold and the number of possible HCC cases was in the range of 0.0002-0.0021 cases per year for 105 individuals. The results suggest low health risks due to AFM1 exposure for the whole population. Still, this risk is not non-existent, especially for children as they have a higher ratio of the population exposed to risk associated AFM1 levels, with MOE values below risk indicating threshold starting at 77.5th percentile.

Dietary exposure to acrylamide of university students in Ningxia of Northwest China and the effect on their neurobehavioral performance and oxidative stress in serum.

This study aims to investigate dietary exposure to acrylamide (AA) and also make an assessment of its effect on the neurobehavioral performance and oxidative stress in the serum of university students in Ningxia. The place primarily consists of arid, dry desert, and wheat-based foods are the staple food there. A total of 803 university students in Ningxia participated in this cross-sectional study. Diet intake of AA was estimated with FFQ. The AA risk was calculated as margin of exposure (MOE) values. NCTB questionnaires were used to assess neurobehavioral performance. The serum oxidative stress levels of the university students were measured as GSH, MDA, and SOD. The mean for AA exposure of university students was 0.515 μg kg-1 bw day-1. The highest contributor was traditional Chinese grain products, representing 34.71% of the total daily AA intake. Followed were deep-fried potato products, traditional Western grain products, soft drinks, and nuts, which accounted for 23.87%, 16.59%, 11.15%, and 11%, respectively. The median AA exposure were 480 (BMDL10=0.18 mg kg-1 bw day-1) and 827 (BMDL10=0.31 mg kg-1 bw day-1), respectively. The results indicated that diet AA may have an effect on the emotional status and neurobehavior among this population. We observed no significant differences in oxidative stress under the three levels of AA exposure (p > .05). It suggests a health concern for university students in Northwest China that should get society's attention.

Concentrations and human exposure to hexabromocyclododecane and tetrabromobisphenol A from the indoor environment in Bangkok metropolitan area, Thailand

Aim: This study investigated hexabromocyclododecane (HBCDD) and tetrabromobisphenol A (TBBPA) concentrations in indoor dust from houses, offices, and cars and estimated toddler and adult exposure to HBCDD and TBBPA through dust ingestion. Methods: The concentrations of HBCDD and TBBPA were measured in 47 indoor dust samples collected from the Bangkok metropolitan area, Thailand. All samples were analyzed for HBCDD and TBBPA using LC-MS/MS. The estimated daily intake (EDI) through dust ingestion was calculated from the median and 95th percentile concentrations of HBCDD and TBBPA. Results: HBCDD was detected in 47% of samples, and TBBPA was detected in all samples. The median concentrations of HBCDD were 6.7 ng g-1, &lt;0.7 ng g-1, and &lt;0.7 ng g-1 in cars, houses, and offices, respectively. The isomer composition of ∑HBCDD in dust was: α-HBCDD (40%-54%), γ-HBCDD (19%-40%), and β-HBCDD (17%-28%). In contrast, TBBPA was observed at higher concentrations, with median values of 674, 67, and 22 ng g-1 in offices, houses, and cars, respectively. Under a median exposure scenario, toddlers were exposed to 0.05 ng kg-1 bw day-1 for HBCDD and 0.25 ng kg-1 bw day-1 for TBBPA, with adults exposed to 0.01 and 0.06 ng kg-1 bw day-1 for HBCDD and TBBPA respectively. Conclusion: Concentrations of HBCDD in dust from Thai cars, homes, and offices are lower than those of TBBPA following the listing of HBCDD in the Stockholm Convention on Persistent Organic Pollutants and limited use of HBCDD in Thailand in applications such as building insulation foam. Concentrations of TBBPA in office dust significantly exceeded (P &lt; 0.05) those in house and car dust owing to the greater number of electronic appliances and poor natural ventilation in offices. EDIs for Thai toddlers exceeded those of adults under both median and high-end exposure scenarios. However, EDIs of HBCDD and TBBPA for the general Thai population were below the corresponding oral reference dose guidelines.

Nitrite content in meat products from the Serbian market and estimated intake

The aim of this study was to determine levels of nitrites in some meat products sold on the Serbian market over a period of 3 years (2018-2020) and to compare results with maximum residue levels as well to discuss dietary exposure of the Serbian adult population to nitrites.A total of 1291 meat product samples, produced by the Serbian meat industry or imported (509 dry fermented sausages, 37 semi-dry fermented sausages, 451 finely minced cooked sausages and 294 coarsely minced cooked sausages), were obtained from the Serbian retail market during 2018-2020.Higher mean levels of nitrite content, expressed as NaNO2, were found in cooked sausages (40.35 mg kg-1, finely minced and 33.75 mg kg-1, coarsely minced) compared to fermented sausages (1.86 mg kg-1 dry fermented and 1.83 mg kg-1, semi-dry fermented).The average dietary exposure to nitrites, expressed as nitrite ion, for the Serbian adult population varies from 0.001 to 0.015 mg kg-1body weight (BW) day-1 and was far below the European acceptable daily intake (0.07 mg kg-1 BW day-1). In conclusion, the concentrations of nitrite in all meat products were below established maximum permitted levels (national and European), indicating that the use of nitrite as a food additive in Serbia is generally in line with existing regulations.

Risk of dietary and breastmilk exposure to mycotoxins among lactating women and infants 2-4 months in northern India.

Mycotoxins are carcinogenic secondary metabolites of fungi that have been linked to infant growth faltering. In this study, we quantified co‐occurring mycotoxins in breast milk and food samples from Haryana, India, and characterized determinants of exposure. Deterministic risk assessment was conducted for mothers and infants. We examined levels of eight mycotoxins (Aflatoxin B1, B2, G1, G2, M1, M2; Ochratoxin A, B) in 100 breast milk samples (infants 2–4 months) using ultra‐high‐performance liquid chromatography tandem mass spectrometry. Aflatoxin B1 (AFB1), fumonisin B1 (FB1) and deoxynivalenol (DON) were detected in several food items (n = 298) using enzyme‐linked immunosorbent assays. We report novel data on the presence of mycotoxins in breast milk samples from India. Whereas breast milk concentrations (AFM1 median: 13.7; range: 3.9–1200 ng/L) remain low, AFM1 was detected above regulatory limits in 27% of animal milk samples. Additionally, 41% of infants were above provisional maximum tolerable daily intake (PMTDI) limits for AFM1 due to consumption of breast milk (mean: 3.04, range: 0.26–80.7 ng kg−1 bw day−1). Maternal consumption of breads (p < 0.05) was associated with breast milk AFM1 exposure. AFB1 (μg/kg) was detected in dried red chilies (15.7; 0–302.3), flour (3.13; 0–214.9), groundnuts (0; 0–249.1), maize (56.0; 0–836.7), pearl millet (1.85; 0–160.2), rice (0; 0–195.6), wheat (1.9; 0–196.0) and sorghum (0; 0–63.5). FB1 (mg/kg) was detected in maize (0; 0–61.4), pearl millet (0; 0–35.4) and sorghum (0.95; 0–33.2). DON was not detected in food samples. Mothers in our study exceeded PMTDI recommendations for AFB1 due to consumption of rice and flour (mean: 75.81; range: 35.2–318.2 ng kg−1 bw day−1). Our findings show the presence of Aflatoxin B1 and M1 at various levels of the food chain and in breast milk, with estimated intakes exceeding PMTDI recommendations. Aflatoxins are known carcinogens and have also been linked to stunting in children. Their presence across the food system and in breast milk is concerning, thus warranting further research to replicate and expand on our findings and to understand implications for maternal and child health.

A SURVEY OF PARABENS IN COMMERCIAL BABY WIPES FROM BRAZIL AND ESTIMATION OF DAILY EXPOSURE

Several studies have shown endocrine-disrupting effects of parabens. Parabens are a group of antimicrobials used as preservatives in a wide variety of products, mainly in personal care products. However, little information is available regarding the occurrence of parabens in baby products. In this study, the concentrations of five commonly used parabens, methyl-, ethyl-, propyl-, butyl- and, benzyl-paraben in 50 Brazilian baby wet wipes were analyzed by liquid chromatography coupled to mass spectrometry. All samples contained parabens, and the total concentrations ranged from 16 to 332,470 ng g-1 (geometric mean: 5344 ng g-1). Methyl-paraben, ethyl-paraben, propyl-paraben, and butyl-paraben were found in >65% of the samples. 24 out of 50 samples exceed the permitted value of 0.4 % for methyl-paraben for their use in personal care products. Although, propyl-paraben and butyl-paraben are forbidden in cosmetic products designed for application on the nappy area of children under three years of age, the detection rate of them were 94 and 70 %, respectively. Based on the measured concentrations and use frequency of baby wipes the estimated daily intake of parabens was calculated. The median estimated daily intake values of total concentrations of parabens for babies of one year old was 391 ng kg-1 bw day-1. In conclusion, babies and children may be exposed to high levels of parabens through use of baby wipes. It is also worth to mention that two forbidden parabens were frequently detected.

Frequency and levels of mycotoxins in beer from the Mexican market and exposure estimate for deoxynivalenol mycotoxins

The aim of the present study was to evaluate the occurrence of 23 mycotoxins in beer purchased in Mexico and to assess two exposure scenarios in the Mexican population through beer consumption. Multi-mycotoxin analysis of a total of 61 different beers (132 samples) was carried out using UHPLC-MS/MS equipment. Probability density functions were used to describe mycotoxins contamination. The daily intake of mycotoxins was estimated using a semi-probabilistic approach, applying the Monte Carlo method. Deoxynivalenol (DON) and its metabolites (deoxynivalenol-3-glucoside (DON3G) and 3-acetyl-deoxynivalenol (3ADON)) were the mycotoxins found in higher proportions in contaminated samples. None of the other mycotoxins overpassed the limit of quantification (LOQ) of the method. The combined intake of DON and its analogues ranged from 5.24 to 86.59ngkg-1bwday-1, which represent from 1.20 to 19.83% of the DON TDI. The results suggest that depending on the individual consumption of beer and depending on the type of beer, the intake of DON via beer could represent a significant percentage of the tolerable daily intake (TDI).

Effects of diisononyl phthalate (DiNP) on the endocannabinoid and reproductive systems of male gilthead sea bream (Sparus aurata) during the spawning season.

Diisononyl phthalate (DiNP) is a plasticizer used to improve plastic performance in a large variety of items whichhas been reported asan endocrine-disrupting chemical (EDC) in several organisms. The endocannabinoid system (ECS) is a cellular signaling system, whose functionality is tightly involved with reproductive function. The aim of the present study was the assessment of the effects of DiNP on the gonadal ECS and on the reproductive function of male gilthead seabream Sparus aurata, an important marine aquacultured species in Europe, during the reproductive season. Fish were fed for 21 days with two diets contaminated with different nominal concentrations of DiNP (DiNP LOW at 15µg DiNP kg-1 bw day-1 and DiNP HIGH at 1500µg DiNP kg-1 bw day-1), based on the tolerable daily intake (TDI) ruled by the European Food Safety Authority for humans. The transcription of several genes related to the ECS was affected by the DiNP. Specifically, DiNP reduced the levels of endocannabinoids and endocannabinoid-like mediators, concomitant with the increase of fatty acid amide hydrolase (FAAH) activity. At the histological level, DiNP LOW induced the highest occurrence of individuals with regressed testes. Steroidogenesis was affected significantly, since plasma 11-ketotestosterone (11-KT), the main active androgen in fish, was significantly decreased by the DiNP HIGH treatment, while plasma 17β-estradiol (E2) levels were raised, associated with an increase of the gonadosomatic index (GSI). Additionally, the level of testosterone (T) was significantly increased in the DiNP LOW group, however, the same DiNP concentration reduced the levels of 17,20β-dihydroxy-4-pregnen-3-one (17,20β-P). The production of sperm was in general not affected, since spermiation index, sperm density, survival and the duration of forward motility did not exhibit any changes compared to controls. However, computer-assisted sperm analysis (CASA) showed that DiNP reduced the percentage of motile cells. The results clearly suggest a negative effect of DiNP via the diet on the male endocrine system of gilthead sea bream during the reproductive season.

Bioaccessibility and Human Exposure Assessment of Cadmium and Arsenic in Pakchoi Genotypes Grown in Co-Contaminated Soils.

In many countries cadmium (Cd) and arsenic (As) commonly coexist in soils contaminated by mining activities, and can easily enter the human body via consumption of leafy vegetables, like the popularly consumed pakchoi (Brassica chinensis L.), causing major health concerns. In the present study, bioaccessibility and human exposure of Cd and As were assessed in twenty genotypes of pakchoi cultured at two different levels of co-contamination to identify low health risk genotypes. The bioaccessibilities of Cd and As represent a fraction of the total metals content could be bioaccessible for human, in the present study, significant differences in pakchoi Cd and As bioaccessibility were observed among all tested genotypes and co-contaminated levels. Cd and As bioaccessibility of pakchoi were in the ranges of 24.0–87.6% and 20.1–82.5%, respectively, for in the high level co-contaminated soils, which was significantly higher than for low level co-contaminated soils with 7.9–71.8% for Cd bioaccessibility and 16.1–59.0% for As bioaccessibility. The values of bioaccessible established daily intakes (BEDI) and the total bioaccessible target hazard quotients (TBTHQ) of Cd and As were also considerably higher in high level co-contaminated soils than in low level co-contaminated soils. Two genotypes (Meiguanqinggengcai and Zhenqing60F1) contained relatively low concentrations and bioaccessible Cd and As and, their BEDI and TBTHQ for Cd and As ranged below the tolerable limits set by the FAO/WHO (BEDI of Cd < 0.83 μg kg−1 bw day−1, BEDI of As < 3 μg kg−1 bw day−1) and United States Environmental Protection Agency (TBTHQ for Cd and As < 1), this applied for both levels of co-contaminated soils for adults and children. Consequently, these findings suggest identification of safe genotypes in leafy vegetable with low health risk via genotypic screening and breeding methods could be a useful strategy to ensure the safety of food crops grown in those Cd and As co-contaminated fields due to mining activities.

&lt;b&gt;Maternal and fetal toxicity of Wistar rats exposed to herbicide metolachlor

Metolachlor is a selective pre-emergent herbicide widely used in agriculture to control weeds. The aim of this study was to evaluate the possible effects of metolachlor on reproductive performance of adult rats, as well as its teratogenic potential when administered during the period of organogenesis. Pregnant adult female rats were allocated into 4 experimental groups (n = 10 group-1), that received 0 (control); 150 (TA); 300 (TB); or 1000 mg kg-1 bw day-1 (TC) of metolachlor, by gavage, from the 6th to 15th gestational day (GD). There is reduction in the weight gain of the animals from TB and TC groups compared to the control group. Liver and placenta weights were reduced in TB and TC groups, respectively, while the percentage of post-implantation loss was increased in the TC group. There were no external malformations in either rat of the control or treated groups. However, an increased incidence of skeletal anomalies and visceral anomalies (especially in the urogenital system) was observed in TC group. These results demonstrate that exposure of pregnant rats to metolachlor can lead to signs of general toxicity, late embryonic losses and congenital anomalies.

Toxic effects of arsenic on semen and hormonal profile and their amelioration with vitamin E in Teddy goat bucks.

The present environmental study has been planned to investigate the toxic effects of arsenic on reproductive functions of Teddy bucks as well as to examine whether these toxic effects are ameliorated by vitamin E. Sixteen adult Teddy bucks were divided randomly into four equal groups A, B, C and D with following treatment: A (control), B (sodium arsenite 5mgkg-1 BWday-1 ), C (vit E 200mgkg-1 BWday-1 + Arsenic 5mgkg-1 BWday-1 ) and D (vit E 200mgkg-1 BWday-1 ). This treatment was continued for 84days. Semen quality parameters were evaluated weekly. Male testosterone, luteinising hormone (LH), follicle-stimulating hormone (FSH) and cortisol levels were measured through enzyme-linked immunosorbent assay (ELISA) after every 2weeks. The data were subjected to two-way analysis of variance followed by Duncan test for multiple comparisons. Semen evaluation parameters were reduced significantly (P<0.05) in arsenic-treated animals. The serum hormonal profile of testosterone, LH and FSH was reduced significantly (P<0.05) in arsenic group, while the serum level of cortisol was increased. Vitamin E alleviated the toxic effects of arsenic on semen and hormonal parameters. It may be concluded from this study that sodium arsenite causes major toxicity changes in semen and hormonal profile in Teddy goat bucks and vitamin E has ameliorative effects on these toxic changes.

Concentrations, health risks and sources of polycyclic aromatic hydrocarbons in Nigerian honey

The concentrations of the US EPA 16 priority polycyclic aromatic hydrocarbons (PAHs) were measured in honey samples collected from different regions of Nigeria with a view to providing information on the extent of contamination, regional profiles, sources and risks of PAHs in this food type. The concentrations of the PAHs were determined by using gas chromatography-mass spectrometry after extraction by ultra-sonication with n-hexane and dichloromethane. The concentrations of ∑16 PAHs in the honey samples ranged from 169-522 μg kg-1, 97.2-1980 μg kg-1, 180-641 μg kg-1 and 122-357 μg kg-1 for South- East, South-West, Niger Delta, and North Central regions respectively. The compositional patterns of PAHs in the analyzed honey samples followed the order: 5-rings>4-rings>3-rings>6-rings>2-rings. The estimated daily intake values from consumption of these honey samples ranged from not detected (nd) to 1.9 ng kg-1 bw day-1, nd to 5.9 ng kg-1 bw day-1, nd to 18 ng kg-1 bw day-1 and 0.6 to 33 ng kg-1 bw day-1 for BaP, PAH2, PAH4 and PAH8 respectively. The incremental life cancer risk and margin of exposure values for the majority of the samples indicate that there is no risk associated with the consumption of these honey samples. The PAH isomeric ratios and principal component analysis indicated that combustion of fossil fuels, natural gas and biomass, and automobile emissions were the main sources of PAHs in these samples from the different regions of Nigeria.

Disseminated aspergillosis due to Aspergillus flavus in an experimental model: efficacy of azole therapy.

The aim of this investigation was to create a reproducible experimental model of disseminated Aspergillus flavus aspergillosis, and to compare the relative therapeutic efficacies of itraconazole and fluconazole in this model. Temporarily immunosuppressed male Wistar rats received intravenous challenge by A. flavus conidia. Treatment was initiated 24 h later with oral itraconazole (1 mg kg-1 BW day-1), oral fluconazole (1 mg kg-1 BW day-1) or excipient only (infected-untreated rats); this was continued for 10 days. At this time, although 100% mortality had occurred among all infected-untreated rats, no mortality was noted among the control-uninfected, infected-itraconazole-treated or infected-fluconazole-treated rats. After killing, essential organs were processed for microbiological and histopathological studies. Aspergillus flavus was recovered in high colony counts from the organs of infected-untreated rats (lungs > liver > brain > kidneys), but in significantly lower colony counts, or not at all, from the organs of itraconazole-treated and fluconazole-treated rats. Histopathological alterations were pronounced in tissues of infected-untreated rats, but less so in treated rats. These data suggest that administration of itraconazole or fluconazole sufficiently early may prevent, or retard, progression of lesions in disseminated aspergillosis.

Organochlorine pesticide residues in cow's milk from a tropical region of Mexico

A monitoring study was conducted to assess the magnitude of DDT [(1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane)] and HCH (hexachlorocyclohexane) contamination of bovine milk from the central tropical region of Mexico as the chemicals are extensively used in livestock and public-health programmes. Among pesticide residues analysed, the milk samples collected from Tlalixcoyan showed a mean level of γ-HCH (0.128 mg kg-1), which was significantly higher than residues in milk samples from Medellin (0.049 mg kg-1) and Paso San Juan (0.022 mg kg-1). The mean level of pp'-DDE in Medellin samples (0.039 mg kg-1) was significantly higher than in Paso San Juan (0.018 mg kg-1) and Tlalixcoyan (0.024 mg kg-1) milk samples. The pp '-DDT mean level from Medellin milk samples (0.089 mg kg-1) was significantly higher than the levels detected in the other two areas. The highest mean Σ-DDT level detected in Medellin samples (0.146 mg kg-1) was three times the FAO/WHO tolerance level. The highest acceptable daily intakes calculated for Σ-DDT were 0.017 μg kg-1 bw day-1 for adults and 0.530 μg kg-1 bw day-1 for infants; for γ-HCH residues, they were 0.021 μg kg-1 bw day-1 for adults and 0.666 μg kg-1 bw day-1 for infants, indicating that infants are more exposed to pesticide residues. Results indicate that cattle exposure to HCH and DDT results in high levels in dairy milk and a potential health risk for consumers.

Effects of caffeine on human health

Caffeine is probably the most frequently ingested pharmacologically active substance in the world. It is found in common beverages (coffee, tea, soft drinks), in products containing cocoa or chocolate, and in medications. Because of its wide consumption at different levels by most segments of the population, the public and the scientific community have expressed interest in the potential for caffeine to produce adverse effects on human health. The possibility that caffeine ingestion adversely affects human health was investigated based on reviews of (primarily) published human studies obtained through a comprehensive literature search. Based on the data reviewed, it is concluded that for the healthy adult population, moderate daily caffeine intake at a dose level up to 400 mg day-1 (equivalent to 6 mg kg-1 body weight day-1 in a 65-kg person) is not associated with adverse effects such as general toxicity, cardiovascular effects, effects on bone status and calcium balance (with consumption of adequate calcium), changes in adult behaviour, increased incidence of cancer and effects on male fertility. The data also show that reproductive-aged women and children are ‘at risk’ subgroups who may require specific advice on moderating their caffeine intake. Based on available evidence, it is suggested that reproductive-aged women should consume ⩽ 300 mg caffeine per day (equivalent to 4.6 mg kg-1 bw day-1 for a 65-kg person) while children should consume ⩽ 2.5 mg kg-1 bw day-1.

Intake estimation of polychlorinated dibenzo-p-dioxins, dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs) in salmon: the inclusion of uncertainty

Dioxins and dioxin-like PCBs are given toxic equivalency factors (TEFs) in order to calculate the combined toxic equivalence (TEQ) of these contaminants in a sample of food. This study calculates the probability of an average consumer exceeding the recommended tolerable daily intake of 1–4 pg WHO-TEQ kg-1 bw day-1 as the amount of salmon in the diet is increased. Probabilistic risk analysis is used to account for the known uncertainties in this calculation. When the TEF uncertainty was excluded with no salmon consumption, the background dietary intake ranged from 1.36 to 1.78 pg TEQ kg-1 bw day-1. A weekly consumption of three standard salmon portions resulted in a 36% chance of exceeding the upper limit of the TDI. Inclusion of the TEF uncertainty increased the background dietary intake range from 2.1 to 4.4 pg TEQ kg-1 bw day-1, and the weekly consumption of one salmon portion resulted in a 79% chance of the average consumer exceeding the upper TDI. The most important factors contributing to the uncertainty in these results were, in order of magnitude, the TEF for PCB 126 and the sampling uncertainty (sample size) followed by the measurement uncertainty of PCB 126. We recommend that it is more important to increase sample size and produce more precise estimates in the TEF than to improve analytical accuracy.