Shrimp is one of the major export products in South Asian countries and also an eminent source of nutrition for humans. Hence, any negative effect of this industry may affect not only the country’s economy but also human health. Therefore, in this study, we aimed to assess heavy metal contamination and associated human health risks in cultured shrimp (Penaeus monodon) and aquaculture sludge collected from three shrimp farms of the Cox’s Bazar district, Bangladesh. The results showed that among the eight metals studied, Pb (17.75 ± 1.5 mg/kg) and Cu (9.43 ± 2.8 mg/kg) levels in all shrimp samples were higher than the recommended limit, whereas the concentrations of Cd (0.09 ± 0.03 mg/kg), Mn (4.83 ± 2.2 mg/kg), As (0.04 ± 0.02 mg/kg), Hg (0.02 ± 0.006 mg/kg), Zn (18.89 ± 2.9 mg/kg) and Cr (0.69 ± 0.6 mg/kg) were within the permissible level. The concentrations of Mn (1043.37 ± 59.8 mg/kg), Cr (30.38 ± 2.1 mg/kg), Zn (74.72 ± 1.13 mg/kg) and Cu (31.14 ± 1.4 mg/kg) in the sludge of all farms were higher than the recommended limit, whereas the concentrations of Pb (20.23 ± 1.9 mg/kg), Cd (0.09 ± 0.2 mg/kg), As (0.44 ± 0.34 mg/kg) and Hg (0.08 ± 0.02 mg/kg) in all sludge samples were lower than the threshold limits. However, the estimated daily intake (EDI), targeted hazard quotient (THQ) and hazard index (HI) assessed for potential human health risk implications suggested that Pb and Cr may pose non-carcinogenic health effects, although carcinogenic risks (CR) values were acceptable for consumers. However, the pollution load index (PLI) of the studied area was below 1, which indicates low deterioration of the area. Geoaccumulation index (Igeo) and contamination factor (CF) analyses revealed that study area is unpolluted and sludge is enriched with metals in the following order: Mn > Zn > Cu > Cr > Cd > Hg > Pb > As.

Trace-element or heavy-metal pollution has emerged as a serious concern in terms of both environmental and human health issues. This study measured six trace and toxic heavy metals (Pb, Cd, Cr, Ni, Cu, and Zn) in four marine fish and shrimp species to assess their accumulation levels and evaluate the risks to human health. The mean concentrations of the metals in fish and shrimp species (Labeo bata, Sillaginopsis panijus, Platycepalus fuscus, and Penaeus monodon) followed the decreasing order of Zn (40.8 ± 9.7 μg/g) > Cu (17.8 ± 7.1 μg/g) > Pb (6.2 ± 1.8 μg/g) > Ni (0.4 ± 0.3 μg/g) > Cd (0.06 ± 0.02 μg/g > Cr (below detection level). Among the metals, only Pb in finfish and Pb, Cu, and Zn in shrimp samples exceeded the national recommended limits, representing possible risks to consumers. The mean metal concentrations in the studied fish/shrimp species followed the descending order of P. monodon > S. panijus > P. fuscus > L. bata, which implies that bottom dwellers and omnivores had higher levels of metals. However, the estimated daily intake (EDI) concentrations of Zn and Cu for the studied species were lower than the RDA (Recommended Daily Allowance). In addition, the Target Hazard Quotient (THQ) and hazard index (HI or TTHQ) values for all species were < 1, indicating that consumers might not experience carcinogenic health risks. A strong significant (p < 0.05) correlation between Cu and Pb (r = 0.623) and Zn and Cu (r = −0.871) indicated they were from the same source of origin. Cluster analysis (CA) and principal component analysis (PCA) demonstrated possible anthropogenic sources of toxic metals in the study area, specifically industrial wastes and agricultural chemicals.

OBJECTIVE: To determine the prevalence of tuberculosis (TB) drug resistance in Bangladesh. DESIGN: Weighted cluster sampling among smear-positive cases, and standard culture and drug susceptibility testing on solid medium were used. RESULTS: Of 1480 patients enrolled during 2011, 12 falsified multidrug-resistant TB (MDR-TB) patients were excluded. Analysis included 1340 cases (90.5% of those enrolled) with valid results and known treatment antecedents. Of 1049 new cases, 12.3% (95%CI 9.3–16.1) had strains resistant to any of the first-line drugs tested, and 1.4% (95%CI 0.7–2.5) were MDR-TB. Among the 291 previously treated cases, this was respectively 43.2% (95%CI 37.1–49.5) and 28.5% (95%CI 23.5–34.1). History of previous anti-tuberculosis treatment was the only predictive factor for first-line drug resistance (OR 34.9). Among the MDR-TB patients, 19.2% (95%CI 11.3–30.5; exclusively previously treated) also showed resistance to ofloxacin. Resistance to kanamycin was not detected. CONCLUSION: Although MDR-TB prevalence was relatively low, transmission of MDR-TB may be increasing in Bangladesh. MDR-TB with fluoroquinolone resistance is rapidly rising. Integrating the private sector should be made high priority given the excessive proportion of MDR-TB retreatment cases in large cities. TB control programmes and donors should avoid applying undue pressure towards meeting global targets, which can lead to corruption of data even in national surveys.

A very simple, ultra-sensitive and highly selective non-extractive spectrophotometric method for the determination of trace amounts of molybdenum(VI) in solution using benzoylacetone-benzoylhydrazone (Bzac-BH) has been developed. Bzac-BH reacts in a slightly acidic solution (0.0003–0.002 M H₂SO₄) with molybdenum(VI) to give an orange chelate which has an absorption maximum at 447 nm. The reaction is instantaneous and the absorbance remains stable for over 12 h. The average molar absorption co-efficient and Sandell's sensitivity were found to be 6.3 × 10⁵ L mol⁻¹ cm⁻¹ and 15 ng cm⁻² of molybdenum(VI), respectively. Linear calibration graphs were obtained for 0.05–2 mg L⁻¹ of molybdenum(VI). The stoichiometric composition of the chelate is 1 : 1 (Mo : Bzac-BH). A large excess of over 50 cations, anions and complexing agents (such as chloride, phosphate, azide, thiosulfate, thiourea, SCN⁻, etc.) do not interfere with the determination. The developed method was successfully used in the determination of molybdenum levels in several Standard Reference Materials (alloys and steels) as well as in some environmental waters (inland and surface), biological samples (human blood and urine), soil samples, solutions containing both molybdenum(V) and molybdenum(VI) and complex synthetic mixtures. The method has high precision and accuracy (s = ±0.01 for 0.5 mg L⁻¹).