Baseline Health Risk Assessment of Trace Metals in Bivalve Shellfish From Commercial Growing Areas in the Estuaries of Ashtamudi and Vembanad (Kerala, India)

Trace metal concentrations were monitored in the yellow clam (Paphia malabarica), green mussel (Perna viridis) and edible oyster (Crassostrea madrasensis) from growing areas in the Ashtamudi and Vembanad estuaries, Kerala. Ranges of mean annual concentrations (mg/kg) were Ni (0.46–0.65); Co (2.87–3.49); Fe (80.0–119.4); Mn (3.88–9.38); Zn (40.8–76.2); Pb (1.28–2.00); Cu (1.59–4.38). In Ashtamudi, clams had higher mean concentrations of Ni, Co, Fe, Mn and Pb than oysters. Mean concentrations of Ni, Pb (in all species), Zn (in clams and mussels) and Cu (in mussels) did not exceed maximum permissible limits mandated by the Food Safety and Standards Authority of India. Mean Mn concentrations exceeded the World Health Organization guideline in the three species while mean Fe concentrations in clams and oysters did not exceed the guideline. Target hazard quotients were generally ≤ 1, except for a few Pb results in clams and mussels. Although results suggest no health risk to consumers for the reference doses, daily intakes and elements considered, regular monitoring of trace metals is recommended to maintain consumer protection given increasing anthropogenic and climatic pressures on the shellfish growing areas.

Influence of Meteorology on Fine Particles Concentration in Vitória Metropolitan Region During Wintertime

Fine particles (PM2.5) are harmful to human health especially during periods of limited dispersion when the concentrations build up. This is a common occurrence in Southern Brazil in the dry season when high-pressure stationary systems inhibit vertical dispersion and reduce wind speed. The objective of this study was to evaluate the PM2.5 concentrations in the Region of Greater Vitória during the winter of 2013, and to assess the influence of the large-scale meteorological circulation on its concentration. An experimental campaign was carried out to determine the mass of PM2.5 at six urban sites and particle number concentration. The average PM2.5 concentrations varied from 9.70 μg m-3 to 14.36 μg m-3 with the average daily maximum reaching 29.35 μg m-3, exceeding the World Health Organization guideline (24-h average: 25 μg m-3). The particle size distribution showed a larger number of particles from 18 to 21 h (local time), indicating that the main vehicular emissions are the main sources. During the winter, rainfall associated with cold fronts were responsible for a decrease in the particulate concentrations. In contrast, the occurrence of high-pressure systems led to an increase in particle concentrations, due to stagnant conditions.

A review of the analytical methodology to determine Radium-226 and Radium-228 in drinking waters

Radium-228 (228Ra) and Radium-226 (226Ra) isotopes in drinking water are significant from the aspect of radiation protection and human health. In this paper, the three most common preconcentration methods, i.e.coprecipitation, absorption and evaporation, were reviewed with emphasis on routinely measurement techniques. The reviewed measurement techniques include low background γ-spectrometry, α-spectrometry and liquid scintillation counting. The γ-spectrometry technique is the good selection, when the maximum sensitivity is considered. The Environmental Protection Agency guideline has provided the maximum concentration level 0.74 Bq/L for 226Ra and 228Ra. Also, the World Health Organization guideline limit is 1 Bq/L and 0.1 Bq/L for 226Ra and 228Ra, respectively.

Sugar Restriction for Caries Prevention: Amount and Frequency. Which Is More Important?

The World Health Organization guideline to use less sugar may be an opportunity and support for dentistry in its goal to get the message of using less sugar across to the public. Two ways (with all the combinations of these) to achieve a reduction of sugar consumption are the reduction of the amount of sugar in products or the reduction of the frequency of consumption of sugar-containing products. Which sugar-reducing strategy is best for caries prevention? To answer this question, this manuscript discusses the shape of the dose-response association between sugar intake and caries, the influence of fluoridated toothpaste on the association of sugar intake and caries and the relative contribution of frequency and amount of sugar intake to caries levels. The results suggest that when fluoride is appropriately used, the relation between sugar consumption and caries is very low or absent. The high correlation between amount and frequency hampers the decision related to which of both is of more importance, but frequency (and stickiness) fits better in our understanding of the caries process. Reducing the amount without reducing the frequency does not seem to be an effective caries preventive approach in contrast to the reciprocity. Goals set in terms of frequency may also be more tangible for patients to follow than goals set in amount. Yet, in sessions of dietary counselling to prevent dental caries, the counsellor should not forget the importance of quality tooth brushing with fluoride toothpaste.

Public health responses to toxic cyanobacterial blooms: perspectives from the 2016 Florida event

In June 2016, massive cyanobacterial blooms occurred in the St. Lucie River in Florida, caused by nutrient and cyanobacterial-laden water releases from Lake Okeechobee. We independently collected and analyzed bloom material for cyanotoxin diversity and concentrations. The concentrations of microcystins, potent hepatotoxins, present in the bloom material greatly exceeded World Health Organization Guideline Values for drinking and recreational water. We also detected the neurotoxins anatoxin-a(S) and β-N-methylamino-L-alanine (BMAA). The Florida State Governor declared a state of emergency, but many affected aquatic recreational areas in St. Lucie County remained open during the bloom event without adequate hazard notification to citizens. During the bloom event, issues with preparedness, communication, sampling, analysis, closures and contingencies were observed. We suggest better ways that cyanobacterial bloom events can be predicted, managed, and mitigated in the future throughout the world. As similar problems with cyanobacterial bloom frequency and occurrence present worldwide, understanding governmental responses to the 2016 Florida incident can help in the development of effective mitigation and management strategies for future bloom events.

Carboxyhaemoglobin Levels among Traders Exposed to Vehicular Emissions in Three Motor Parks in Ibadan, Nigeria

Carbon monoxide (CO) remains a leading cause of work-related chemical poisoning. Vehicular emissions are the primary daily ambient source of CO in urban Nigerian motor parks, where there have been few human exposure studies. Using a cross-sectional comparative design, we assessed carboxyhaemoglobin levels (% COHb), a biomarker of CO exposure, among traders at three motor parks (AMP, IMP, and NMP) and other traders (nonmotor park workers) in Ibadan, Nigeria, using a noninvasive pulse CO-dosimeter (Rad 57). Ninety-three traders were proportionally allocated between motor parks; 93 other traders were selected based on specific study inclusion criteria. Mean ages of motor park traders and other traders were comparable, 37.8±11.1 and 38.7±9.6, respectively. Mean % COHb for traders (range 3–22) at AMP, IMP, and NMP was 11.2±3.8, 11.6±3.1, and 12.2±3.3, respectively, while mean % COHb for other traders was about three times lower, 4.1±1.7 (range 2–8). Overall, mean % COHb for motor park traders, 11.7±3.3, was also significantly higher than for other traders (p<0.05). Nevertheless, mean % COHb for both groups exceeded the current World Health Organization guideline, 2.5%. This study suggested that motor park traders have higher % COHb and thus are highly susceptible to exposure and more vulnerable to known risks of adverse health effects from exposure to CO.