Johann M.R. Antoine

Evaluation of dietary exposure to minerals, trace elements and heavy metals from the muscle tissue of the lionfish Pterois volitans (Linnaeus 1758)

Twenty-five samples of Pterois volitans caught in Jamaican waters were analyzed for 25 essential, non-essential and toxic elements using Graphite Furnace Atomic Absorption Spectrophotometry (GF-AAS), Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) and Instrumental Neutron Activation Analysis (INAA). The mean values for calcium (355 mg/kg), copper (107 μg/kg), iron (0.81 mg/kg), potassium (3481 mg/kg), magnesium (322 mg/kg), manganese (0.04 mg/kg), selenium (0.47 mg/kg), sodium (700 mg/kg) and zinc (4.46 mg/kg) were used to estimate dietary intake. The percentage contribution to provisional tolerable weekly intake for a 70 kg male and a 65 kg female were also estimated for the toxic elements arsenic (1.28% M, 1.38% F), cadmium (0.26% M. 0.28% F), mercury (3.85% M, 4.15% F) and lead (0.17% M, 0.18% F). To further assess the risk of mercury toxicity and the role of mitigation provided by selenium, selenium-mercury molar ratios were calculated for all samples. All samples were shown to have a molar excess of selenium. In addition the suggested selenium health benefit value was calculated, and was positive for all samples. It was concluded that P. volitans appears to contribute modestly to mineral and trace element nutrition, while not being a significant contributor to dietary exposure of toxic elements.

Assessment of the potential health risks associated with the aluminium, arsenic, cadmium and lead content in selected fruits and vegetables grown in Jamaica

Highlights • Thirteen food crops were analysed for aluminium, arsenic, cadmium and lead.• Mean concentrations were used to calculate EDI, THQ and HI.• TCR was calculated for arsenic for all food crops.• The THQ and HI were <1 for all food crops; target cancer risk did not exceed 10−4.• The food crops evaluated pose no undue risk to the consumer.

Agglomerative hierarchical clustering analysis of twenty-six rice samples analysed by instrumental neutron activation analysis and other techniques

As part of the ongoing work on the safety and security of foods grown locally and imported into Jamaica, twenty five rice brands available on the Jamaican market and one sample of locally grown brown rice were collected and analysed for 36 elements using a combination of instrumental neutron activation analysis, total reflection X-ray fluorescence, flame atomic absorption spectrometry and inductively coupled plasma optical emission spectrometry. Quality control for each of the techniques was provided by analysis of reference materials and inter-comparisons of common elements. Agglomerative hierarchical clustering analysis performed on the raw data set identified white, parboiled and brown rice as the major clusters. The element and cluster median concentration in μg/g (for polished, parboiled and brown respectively) for each of the three clusters were Al (8.7, 11.3, 14.9), As (0.20, 0.21, 0.15), Br (12.1, 0.9, 3.4), Ca (60.4, 409.1, 112.5), Co (0.1, 0.09, 0.11), Cr (0.11, 0.10, 0.11), Cs (0.012, 0.004, 0.018), Eu (0.004, 0.004, 0.003), Cu (2.2,2.7, 3.6), Fe (13, 17, 20), K (894,1,815,2,538), La (0.009, 0.014, 0.015), Mg (340, 504, 1,303), Mn (9.7, 14.9, 28.5), Mo (0.7, 1.1, 0.8), Na (5.1, 9.9, 16.9), P (936, 2,328, 3,670), Rb (4.5, 6.1, 7.3), S (1,088,1,308, 1,321), Sb (0.004, 0.006, 0.005), Sc (0.001, 0.002, 0.002), Se (0.09, 0.17, 0.16), Sm (0.001, 0.003, 0.001), Sr (2.0, 1.9, 2.9), V (0.036, 0.041, 0.058), Zn (17.9, 15.3, 22.8). The use of agglomerative hierarchical clustering has proven to be a rapid method for the analysis of the dataset, correctly clustering rice by process that is, polished, parboiled and brown, with sub-clusters that further identified location, cultivars and an adulterated sample. The data validated here has been used to estimate the elemental contribution of rice to the Jamaican diet.

The determination of the inhalable fraction of 40K activity in marijuana (Cannabis sativa L.) buds by instrumental neutron activation analysis and the effective dose to the body

Abstract Total potassium in marijuana (Cannabis sativa L.) buds was determined using instrumental neutron activation analysis. The mass fraction of 40K and its activity were derived using the natural isotopic ratios of potassium. The total potassium in the marijuana buds ranged from 0.84% to 3.15% with a mean mass fraction of 1.93%. The activity concentrations of 40K in the samples of marijuana ranged from 253 to 946 Bq kg−1 with a mean activity concentration of 581 Bq kg−1. The effective dose to the body from smoking marijuana is lower than that for comparable tobacco smoking. Simulated smoking experiments show that over 90% of 40K is retained in the cigarette ash. Accepted methods of determining effective dose to the body from 40K inhalation are likely overestimations for both marijuana and tobacco cigarette smoke.