Polycyclic aromatic hydrocarbons and halogenated persistent organic pollutants in canned fish and seafood products: smoked versus non-smoked products

In this study, levels of several groups of environmental contaminants represented by PAHs, PCBs, organochlorine pesticides and polybrominated diphenyl ethers were determined in various types of canned smoked and non-smoked fish and seafood products (54 samples) obtained from the Czech market. PAHs were detected in all of the studied samples, and at least one of the target halogenated persistent organic pollutants was present above the LOQ in 85% of the samples. The levels of PAHs, PCBs, organochlorine pesticides (mainly DDTs) and polybrominated diphenyl ethers found in the canned products varied in the range of 1.4–116?µg?kg^?1, 0.6–59.6?µg?kg^?1, 0.6–82.7?µg?kg^?1 and 0.1–2.1?µg?kg^?1 can content, respectively. Smoked sprats were the most contaminated fish product (n?=?12) in which the highest levels of both PAHs and persistent organic pollutants were found. In 67% of the samples of smoked sprats in oil, the level of benzo[a]pyrene exceeded the maximum level of 5?µg?kg^?1 established for smoked fish by European Union legislation. The distribution of target analytes between oil and fish fractions was also assessed. Significantly higher levels of PAHs were measured in the oil fraction.     

Estimation of methylmercury intake from the 2007 Chinese Total Diet Study

Methylmercury intake for adult males of twelve provinces in China was estimated by means of the 2007 Chinese Total Diet Study. Methylmercury levels were measured in twelve food groups of each province of four regions and was only found in the aquatic food groups. The range for methylmercury contents of aquatic foods was 3.29–31.60?µg?kg^?1, being 50–87% of total mercury. Methylmercury intakes from aquatic foods for adult males of twelve provinces ranged from 0.003 to 0.138?µg?kg^?1?bw?week^?1 with average of 0.041?µg?kg^?1?bw?week^?1, which were estimated according to methylmercury contents and corresponding aquatic food consumption. Methylmercury intakes for the Chinese population were far below the corresponding provisional tolerable weekly intake (PTWI), which was established by the Joint FAO/WHO Expert Committee on Food Additives (JECFA). Consequently, there was little health risk from methylmercury exposure for the average Chinese population.     

Ethyl carbamate in fermented foods and beverages: dietary exposure of the Hong Kong population in 2007–2008

To evaluate the potential public health risk of ethyl carbamate (EC), EC exposure from fermented foods and beverages for Hong Kong population was estimated. In 276 samples analysed, EC was detected (limit of detection (LOD) at 0.4?µg?kg^?1) in 202 samples (73%), with higher levels in fermented red bean curd (150–650?µg?kg^?1) and yellow wine (140–390?µg?kg^?1), while low or non-detected (ND) in preserved vegetables (ND–10?µg?kg^?1) and fermented tea (ND–15?µg?kg^?1). The estimated dietary exposure from all fermented foods and beverages was 8.27?ng?kg^?1?bw?day^?1, while exposure excluding alcoholic beverages was 5.42?ng?kg^?1?bw?day^?1, with calculated margins of exposure (MOEs) at 3.6?×?10⁴ and 5.5?×?10⁴ respectively. The risk of adverse health effects was low for the average population but higher (MOE?of?10³) for high consumers of alcoholic beverages especially habitual drinkers of alcoholic types with high EC contents.     

Natural occurrence of type-B trichothecene mycotoxins in Korean cereal-based products

Type-B trichothecenes (deoxynivalenol (DON), nivalenol (NIV), fusarenone-X (FUS-X), 15-acetyldeoxynivalenol (15ADON), and 3-acetyldeoxynivalenol (3ADON)) were determined in 338 cereal-based products. Detection limit, quantification limit and mean recovery for five toxins were in the ranges 0.7–2.6?µg?kg^?1, 2.1–7.8?µg?kg^?1 and 73–110%, respectively. The range of occurrence and average level in samples were, respectively, 21–88% and 5.2–121.8?µg?kg^?1 for NIV, 10–96% and 1.7–109.5?µg?kg^?1 for DON, 2–39% and 0.4–3.6?µg?kg^?1 for FUS-X, 0–80% and 0–17.3?µg?kg^?1 for 15ADON, and 0–29% and 0–1.5?µg?kg^?1 for 3ADON. Regarding co-occurrence, 64% of samples had more than two type-B trichothecenes. The estimated daily intakes of NIV, DON, FUS-X, 15ADON, and 3ADON were 0.077, 0.048, 0.004, 0.006 and 0.002?µg?kg^?1?bw?day^?1, respectively. These results suggest that current exposure levels do not indicate the possibility of adverse effects, but consideration of the combined exposure of type-B trichothecenes may be required due to the high frequency of co-occurrence.     

Evaluation of total aflatoxin,nitrate and nitrite levels in layer feed samples of companies producing their own feed in Edincik and Bandırma province of Turkey

Feed contamination by fungi can lead to nutrient losses and detrimental effects on animal health and production. The presence of nitrates and nitrites in food can be harmful to both people and animals. The aim of this study was to determine total aflatoxin, nitrate and nitrite levels in layer feed samples from companies producing their own feed in Edincik and Band?rma provinces in Turkey and to discuss the potential risk to animal health. The results of the analyses indicated that mean total aflatoxin (AFT) ranged from 0.4 to 36.8?µg?kg^?1 and from 0.45 to 47.0?µg?kg^?1 in the year 2007 and the year 2008 samples, respectively. It was determined that nitrate levels were 2.4–10 and 1.7–13?µg?kg^?1 and that nitrite levels were 0–2.4?µg?kg^?1 and 0–2.6?µg?kg^?1 in these years, respectively. The levels of total aflatoxin, nitrate and nitrite in the layer samples could not be considered a risk to poultry health and productivity.     

Survey of aflatoxins in maize tortillas from Mexico City

In Mexico, maize tortillas are consumed on a daily basis, leading to possible aflatoxin exposure. In a survey of 396 2-kg samples, taken over four sampling days in 2006 and 2007 from tortilla shops and supermarkets in Mexico City, aflatoxin levels were quantified by HPLC. In Mexico, the regulatory limit is 12?µg?kg^?1 total aflatoxins for maize tortillas. In this survey, 17% of tortillas contained aflatoxins at levels of 3–385?µg?kg^?1 or values below the limit of quantification (<LOQ) and, of these, 13% were >12?µg?kg^?1 and 87% were below the regulatory limit. Average aflatoxin concentrations in 56 contaminated samples were: AFB₁ (12.1?µg?kg^?1); AFB₂ (2.7?µg?kg^?1); AFG₁ (64.1?µg?kg^?1) and AFG₂ (3.7?µg?kg^?1), and total AF (20.3?µg?kg^?1).     

Occurrence of furan in commercial processed foods in Brazil

Selected commercial processed foods available in the Brazilian market (306 samples) were analysed for furan content using a validated gas chromatography-mass spectrometry method preceded by headspace solid phase micro-extraction (HS-SPME-GC/MS). Canned and jarred foods, including vegetable, meat, fruit and sweet products, showed levels up to 32.8?µg?kg^?1, with the highest concentrations observed in vegetables and meats. For coffee, furan content ranged from 253.0 to 5021.4?µg?kg^?1 in the roasted ground coffee and from not detected to 156.6?µg?kg^?1 in the beverage. For sauces, levels up to 138.1?µg?kg^?1 were found. In cereal-based products, the highest concentrations (up to 191.3?µg?kg^?1) were observed in breakfast cereal (corn flakes), cracker (cream crackers) and biscuit (wafer). In general, these results are comparable with those reported in other countries and will be useful for a preliminary estimate of the furan dietary intake in Brazil.     

Occurrence and intake of deoxynivalenol in cereal-based products marketed in Korea during 2007–2008

The occurrence of deoxynivalenol (DON) was investigated in 514 cereal-based products (corn-based, n = 125; barley-based, n = 96; wheat-based, n = 94; rice-based, n = 199) marketed in Korea during 2007?2008, and estimates of DON intake were determined. Samples were analysed by high-performance liquid chromatography (HPLC) with ultraviolet light (UV) detection after immunoaffinity clean-up. The limits of detection (LOD) and limits of quantification (LOQ) were 2.2 and 5.6 µg kg^–1, respectively. Recoveries and repeatability expressed as coefficients of variation (CV) were 82.3–100% and 2.4–15.3% in beer, bread and dried corn. The incidences and mean levels of DON were 56% and 68.9 µg kg^?1 for corn-based products, 49% and 24.1 µg kg^?1 for wheat-based products, 43% and 7.5 µg kg^?1 for barley-based products, and 16% and 3.4 µg kg^?1 for rice-based products, respectively. The estimated daily intake of DON from the consumption of rice-based, wheat-based, barley-based and corn-based products were 0.0038 µg kg^?1 bw day^?1, 0.0032 µg kg^?1 bw day^?1, 0.0015 µg kg^?1 bw day^?1 and 0.0002 µg kg^?1 bw day^?1, respectively. These values represent 0.38%, 0.32%, 0.25% and 0.01% of the provisional maximum tolerable daily intake (PMTDI) of 1 µg kg^?1 bw day^?1. These results indicate that rice-based products are major contributors to DON exposure in Korea, even though the current exposure level is unlikely to cause adverse health effects.     

Risk assessment of the lead intake by consumption of red deer and wild boar meat in Southern Spain

The presence of heavy metals in big game meat may pose a risk to human health. The main objective of this paper is to carry out a risk assessment study (using a probabilistic and point-estimate approach) of lead intake by consumption of red deer and wild boar meat in Southern Spain based on Spanish data collected in the period 2003–2006. In general, the concentration levels found for wild boar meat (mean?=?1291?µg?kg^?1) were much higher than those observed in red deer meat (mean?=?326?µg?kg^?1). The results from a point-estimate risk assessment showed that the estimated average intake of lead among different exposure scenarios varied from 0.1 to 6.5 and from 0.3 to 38?µg?kg^?1?week^?1 for red deer and wild boar meat, respectively; and from 0.3 to 35?µg?kg^?1?week^?1 for individuals consuming both red deer and wild boar meat, and that the estimated intake of lead by consumption of big game meat differed significantly between hunters and non-hunters, it being higher for hunters. Besides this, results from the probabilistic risk assessment study corroborated the fact that risk is greater in hunter populations, reaching a maximum in individuals consuming only wild boar and both types of meat, with 0.4% and 0.2% of the population above the provisional tolerable weekly intake (PTWI), respectively. Likewise, the hunter populations consuming wild boar and both types of big game meat (red deer and wild boar meat) were exposed to the maximum lead level (56?µg?kg^?1?week^?1), which corresponded approximately to 224% of the PTWI. Further data and studies will be needed to give a complete risk estimation in which it will be crucial to consider the contribution to the lead intake level of other foods in the diet of both population groups.     

Evaluation and validation of two microbiological tests for screening antibiotic residues in honey according to the European guideline for the validation of screening methods

Two microbiological kits based on Bacillus stearothermophilus (Eclipse 50® and Premi®Test) have been evaluated and validated according to the European guideline for the validation of screening methods (January 2010) and in relation to the concentrations recommended by the EU-RL in 2007. Both tests are robust, a fast method and easy to implement. Both tests are applicable to a very large variety of honeys from different floral and geographical origins (rosemary, lavender, scrub, heath, alder, forest, lemon, acacia, chestnut, raspberry, mountain and flowers) as well as honey of different colours (from blank honey to brown honey, including yellow and orange honey). A satisfactory false-positive rate of 5% was obtained for the Eclipse 50® test. The observed detection capabilities CCβ of the Eclipse 50® kit were: chlortetracycline (>75?µg?kg^?1), oxytetracycline (≤200?µg?kg^?1), tetracycline (>100?µg?kg^?1), cloxacillin (≤40?µg?kg^?1), tylosin (≤200?µg?kg^?1), desmycosin (>400?µg?kg^?1), sulfadiazine (≤300?µg?kg^?1), sulfadimethoxine (≤250?µg?kg^?1), sulfamerazine (>300?µg?kg^?1), sulfamethazine (>1000?µg?kg^?1), sulfamethizole (>75?µg?kg^?1), sulfamethoxazole (≤25?µg?kg^?1), sulfanilamide (?1000?µg?kg^?1), sulfaquinoxaline (>75?µg?kg^?1), sulfathiazole (≤250?µg?kg^?1) and lincomycin (>1500?µg?kg^?1). These levels were all higher than the recommended concentrations where they exist. Due to its lack of sensitivity, it cannot be recommended for reliable routine use. The observed CCβ of the Premi®Test kit were: chlortetracycline (10?µg?kg^?1), oxytetracycline (>10?µg?kg^?1), tetracycline (≤10?µg?kg^?1), cloxacillin (≤5?µg?kg^?1), tylosin (≤10?µg?kg^?1), desmycosin (≤15?µg?kg^?1), sulfadiazine (≤25?µg?kg^?1), sulfadimethoxine (≤25?µg?kg^?1), sulfamerazine (≤25?µg?kg^?1), sulfamethazine (≤25?µg?kg^?1), sulfamethizole (≤25?µg?kg^?1), sulfamethoxazole (≤10?µg?kg^?1), sulfanilamide (≤25?µg?kg^?1), sulfaquinoxaline (≤10?µg?kg^?1), sulfathiazole (25?µg?kg^?1) and lincomycin (≤25?µg?kg^?1). The Premi®Test kit could be recommended for reliable use in routine control due to its low detection capabilities (except for aminoglycosides), but the disadvantage is a high false-positive rate of 14%.     

Migration of melamine from can coatings cross-linked with melamine-based resins,into food simulants and foods

Resins based on melamine-formaldehyde and related analogues such as methylolated melamine are used to cross-link coatings used inside food cans and on the metal closures of glass jars. Thirteen commercially coated cans and closures representing 80% of the European market were tested using simulants under realistic industrial heat-processing conditions for canned and jarred foods. The food simulants and the retort conditions used were 3% acetic acid for 1?h at 100°C and 10% ethanol for 1?h at 130°C. The highest migration level seen for melamine into simulant was 332?µg?kg^?1. There was no detectable migration of the melamine analogues cyanuric acid (<1?µg?kg^?1) or ammelide (<5?µg?kg^?1) from any sample. Twelve of the thirteen samples released no detectable ammeline (<5?µg?kg^?1) but the coating giving the highest release of melamine did also release ammeline at 8?µg?kg^?1 with the higher of the two process temperatures used. Migration experiments into food simulant and foods themselves were then conducted using two experimental coatings made using amino-based cross-linking resins. Coated metal panels were exposed to the food simulant 10% (v/v) aqueous ethanol and to three foodstuffs under a range of time and temperature conditions both in the laboratory and in a commercial food canning facility using proprietary time and temperature conditions. The highest migration into a food was 152?µg?kg^?1 from the first coating processed for a long time at a moderate sterilisation temperature. The highest migration into simulant was also from this coating at 220?µg?kg^?1 when processed at 134°C for 60?min, dropping to 190?µg?kg^?1 when processed at 123°C for 70?min. Migration from the second coating was quite uniformly two to three times lower under all tests. These migration results were significantly higher than the levels of melamine extractable using 95% ethanol at room temperature. The experiments show that commercial canning and retorting can be mimicked in an acceptable way using laboratory tests with an autoclave or a simple pressure cooker. The results overall show there is hydrolytic degradation of the melamine cross-linked resins to release additional melamine. There is a strong influence of the temperature of heat treatment applied with foods or simulants but only a minor influence of time of heating and only a minor influence, if any, of food/simulant acidity.     

Co-contamination of aflatoxin B1 and fumonisin B1 in food and human dietary exposure in three areas of China

Aflatoxins and fumonisins are ubiquitous foodborne toxicants and the co-occurrence of these mycotoxins in human foods represents a significant public health concern, which has been strongly associated with human aflatoxicosis, neural tube defects, as well as many types of primary cancers. In this study the co-contamination of aflatoxin B₁ (AFB₁) and fumonisin B₁ (FB₁) in food and human dietary exposure was investigated in residents of three different areas of China. A total of 209 food samples were measured for AFB₁ and FB₁. The median AFB₁ levels were 13.5, 2.3 and 1.3?µg?kg^?1 and the median FB₁ levels were 2.6, 0.4 and 0.3?mg?kg^?1 in corn samples collected from Huaian (a high-risk area for oesophageal cancer), Fusui (a high-risk area for liver cancer) and Huantai (a low-risk area for both oesophageal and liver cancers), respectively. The median level of AFB₁ in plant oil of Fusui was the highest (52.3?µg?kg^?1) among all food samples analysed. Co-contamination of these two mycotoxins was found in corn, rice and wheat flour. Based on measured food consumption data, the averaged daily dietary intake of AFB₁ was 0.397?µg (range?=?0.269–1.218?µg) in residents of Huantai, 1.723?µg (0.224–49.772?µg) in Huaian, and 2.685?µg (1.006–14.534?µg) in Fusui. The averaged FB₁ daily dietary intake was 92.4?µg (range?=?55.0–362.1?µg) for residents of Huantai, 460.0?µg (83.2–2894.5?µg) in Huaian, and 138.6?µg (30.0–10,541.6?µg) in Fusui. These data suggest that the co-exposure to AFB₁ and FB₁ in residents of rural China may contribute to the aetiology of human chronic diseases in high-risk areas.     

Immunoassay based on monoclonal antibodies versus LC-MS: deoxynivalenol in wheat and flour in Southern Brazil

An indirect competitive enzyme-linked immunosorbent assay (ELISA) method using a monoclonal antibody for deoxynivalenol (DON) detection in wheat and flour was standardised and validated (detection limit?=?177.1?µg?kg^?1) and its performance was compared with LC-MS, quantification limit?=140?µg?kg^?1). DON recovery ranged from 88.7% to 122.6% for wheat grain and from 70.6% to 139.3% for flour. Among the 38 wheat samples evaluated, DON was detected in 29 samples (76.3%) by ic-ELISA (281.6–12?291.4?µg?kg^?1) and in 22 samples (57.9%) by LC-MS (155.3–9906.9?µg?kg^?1). The 0.93 correlation coefficient between ic-ELISA and LC-MS data in 19 positive DON wheat samples demonstrated the reliability and efficiency of ic-ELISA. Results indicated that standardised ic-ELISA was suitable for DON screening in wheat samples and the need for continuous monitoring of mycotoxin levels in foodstuffs.     

Determination of acrylamide in Thai-conventional snacks from Nong Mon market,Chonburi using GC-MS technique

Acrylamide in Thai-conventional snacks was analysed by GC/MS with a linear response ranged of 5–50?µg and r ^2?>?0.99. The limit of detection (s/n?=?(3) and limit of quantification (s/n?=?10) were 4 and 15?µg?kg^?1, respectively, and RSD?<?2%. Acrylamide in 19 food samples ranged from <15?µg?kg^?1 to 1.26?mg?kg^?1 with highest concentrations in Kanom Jak. Moderate levels (150–500?µg?kg^?1) were detected mostly in deep-fried products, especially sweet potato and taro crisps, Kanom Kai Hong, banana fritters, durian chips and spring rolls. Thai-conventional snacks possessed low concentrations (<150?µg?kg^?1) including Khao Larm, Pa Tong Koo, sweet banana crisps and deep-fried Chinese wonton. Acrylamide was lowest (<15?µg?kg^?1) in fish strips, rice crackers, Hoi Jor and fried fish balls. Dietary habits by 400 tourists indicate a daily intake of acrylamide <150?ng, well below a toxic dose.     

Determination of furan levels in commercial samples of baby food from Brazil and preliminary risk assessment

Commercial baby food samples available on the Brazilian market (n = 31) were analysed for furan content using a gas chromatography-mass spectrometry method preceded by solid-phase microextraction. A limit of detection of 0.7 µg kg^?1, a limit of quantitation of 2.4 µg kg^?1, mean recoveries varying from 80% to 107%, and coefficients of variation ranging from 5.6% to 9.4% for repeatability and from 7.4% to 12.4% for within-laboratory reproducibility were obtained during an in-house validation. The levels of furan found in the samples were from not detected to 95.5 µg kg^?1. Samples containing vegetables and meat showed higher furan levels as compared with those containing only fruits. An exposure assessment showed furan intakes up to 2.4 µg kg^?1 body weight day^?1 (99th percentile) for babies fed exclusively with commercial baby foods. Margins of exposure obtained from intakes estimated in this work indicated a potential public health concern.     

Simulation of deoxynivalenol intake from wheat consumption in Japan using the Monte Carlo method

The aim of this study was to evaluate the current advisory level in Japan for deoxynivalenol (DON) in foods. To this end, we estimated the intake of DON based on its presence in wheat using a probabilistic computer simulation method. Values for the concentration of DON in wheat were based on those reported in surveys of 638 wheat samples conducted from 2002 to 2004. Data regarding consumption of 108 wheat-based products according to age group were obtained from the 2002 Japan national survey on food consumption. Two data sets on the consumption of wheat-based products and contamination of DON in wheat were analysed using three DON regulatory scenarios: no regulation, 1100 µg?kg^?1 and 2000?µg?kg^?1. Because consumption distributions contained two peaks for each age category, it was assumed that two log-normal distributions for each age category were needed to achieve a better fit to the distribution models. The results of simulated DON intake using the Monte Carlo method showed that children aged 1–6 years have the highest DON intake. However, the 95th percentile of simulated intake of DON in each age group was below the provisional maximum tolerable daily intake (TDI) of 1?µg?kg^?1 body weight using any regulation scenario. The 99th percentile of simulated DON intake in the 1–6-year-old group was greater than TDI at approximately 2?µg?kg^?1 body weight. These results suggest that the current dietary intake of DON from wheat consumption does not exert a significant health effect, but we may need to reconsider the current regulation value for the 1–6-year-old age group. In addition, we may need a better method to fit the distribution to the log-normal distribution better.     

Aflatoxin M1 contamination in cow and buffalo milk samples from the North West Frontier Province (NWFP) and Punjab provinces of Pakistan

A total of 178 milk samples (94 of buffalo and 84 of cow) were randomly taken from Punjab and the North West Frontier Province (NWFP) of Pakistan (n?=?89 in each province) and analysed for the presence of aflatoxin M1 (AFM₁) by HPLC-FLD. From Punjab about 46% of buffalo's and 49% of cow's milks were contaminated with AFM₁ as compared with 52% and 51% for milk samples from NWFP, respectively. Overall, the mean AFM₁ concentration was 0.046?µg?kg^?1 with a maximum of 0.350?µg?kg^?1. All samples complied with the Codex Alimentarius limit of 0.50?µg?kg^?1 for AFM₁ in milk, but 16.3% of samples exceeded the European Union maximum level of 0.05?µg?kg^?1. Another set of 415 buffalo's and cow's milk samples (213 morning milks and 202 evening milks) were analysed. Statistical analysis revealed significant differences (p?<?0.05) between mean AFM₁ concentrations in milk during the morning (0.043?µg?kg^?1) and the evening (0.028?µg?kg^?1) lactation times.     

T-2 and HT-2 toxins in cereals and cereal-based products in South Korea

A total of 214 samples, consisting of brown rice, barley, mixed grains, corn, wheat and wheat flour were analysed for T-2 and HT-2 toxins using high-performance liquid chromatography with fluorescence detection. Recovery and repeatability were 79.9%–107.5% and 4.9%–14.5% for T-2, and 74.0%–106.1% and 5.0%–17.9% for HT-2, respectively. T-2 toxin was detected in 11 (5.1%) of all samples. The highest incidence was found in corn (21.7%) followed by mixed grains and brown rice. Mean of all samples was 1.5–4.1?µg?kg^?1, the maximum level being 41.5?µg?kg^?1 in corn. HT-2 toxin was detected in 126 (58.9%) of all samples, and the mean values were 26.4–59.2?µg?kg^?1. The estimated daily intakes for the sum of T-2 and HT-2 toxins were 2.56, 3.22, 2.53, 0.03, 0.01 and 2.45?ng (kg?bw)^?1?day^?1 in brown rice, barley, mixed grains, corn, wheat and wheat flour, respectively.     

Herbicide contamination of live armclad rockfish,clam and pen shell by moss-control agents used in aquariums of seafood restaurants in Korea

Determination of simazine and diuron by high-performance liquid chromatography-ultraviolet detection (HPLC-UV) in moss-control agents, seawater and fish in aquariums was investigated and validated. The detection limits are 0.2 (simazine) and 0.4?µg l^–1 (diuron) in blank seawater, and 0.20 (simazine) and 0.30 µg kg^?1 (diuron) in blank fish homogenate, while the recoveries ranged from 93.9% to 102.4% with a relative standard deviation?≤?9.8% for simazine and diuron. The method was successfully used in the study of simazine and diuron contamination in live fish stored in seafood restaurant aquaria in Korea. It was found that 0.4–2.3% of simazine and <0.10–3.8% of diuron were included the in moss-control agents tested. Of the 66 sampled aquarium seawaters, simazine was found to be present in four samples (3.8–42?µg?l^?1) while diuron was detected in two samples (1.3–1.6?µg?l^?1). For fish homogenates used in a bioconcentration study, simazine content ranges from 0.17 to 1.8?mg?kg^?1.