A simple assessment of the effect of strontium on the urinary excretion of calcium in Sprague Dawley rats.

This study was aimed at investigating the impact of varying concentrations of strontium (Sr) on calcium (Ca) excretion via the urine and determine its impact on kidney stone formation. Twenty adult male Sprague Dawley rats weighing between 200 and 300 g were selected. The rats were randomly divided into four groups of five. One group was used as a control group while the other three groups were experimental. The diet of the rats was modulated over a 12 week period to investigate the impact of Sr on the urinary excretion of Ca. Urinary samples were collected every 2 weeks from the rats. The rats were fed water ad libitum. After the study the rats were euthanised and their kidneys harvested. Urine and kidney samples from the rats were analysed using Total Reflection X-Ray Fluorescence (TXRF). In the urine excretion of Ca increased with increased intake of Sr in the diet. Sr excretion via the urine also increased with increased dietary intake. There was a correlation of 0.835 at the significance level of 0.01 between Ca and Sr in the urine. However, for the kidneys, the varying concentration of Sr did not impact the retention of Ca in the kidneys. There was increased retention of Sr in the kidneys with increased dietary intake. In this study an increase of Sr in the diet resulted in an increase in urinary excretion of Ca.

Characterization of inorganic elements in common consumer plastics using handheld X-ray fluorescence analyzer.

Plastics are increasingly being used in consumer products due to its versatility in many applications. However, these plastics may contain inorganic elements that may be harmful to humans. To determine any potential health risk of plastics, it was important to characterize elemental composition of plastics and assess usage patterns. To investigate plastic usage in a typical Jamaican household and to characterize the inorganic elements in consumer plastics using XRF analyzer. About 200 questionnaires were distributed to households to determine the types and quantity of plastics. A total of 130 plastic samples from 7 categories were collected and measured for inorganic elements using handheld XRF. Household plastics were mainly used for storage and personal hygiene products. On average, 10% of plastics were recycled, while 30% were burned. Inorganic elements present in plastic samples were Cl > Ti > Ba > Fe > Zn > Sb > Cr > Br > Cu > V > Pb > As. Elemental concentrations varied based on the category of plastics. Green plastics had the highest concentrations of each type of elements. This study provided useful information on characterizing the different types of elements present in common household plastics. Results from the survey were used to assess participants' attitude and behaviors towards plastics usage and disposal. It was important to obtain a profile of plastics waste from a typical household. This will allow for more targeted strategies to reduce plastics pollution.

Addressing the Challenge of Potentially Hazardous Elements in the Reduction of Hypertension, Diabetes and Chronic Kidney Disease in the Caribbean.

BACKGROUND: Environmental surveys have characterized trace elements such as lead (Pb), cadmium (Cd) and arsenic (As) as potential risk factors for non-communicable diseases. There have been few studies conducted in the Caribbean region to explore, define or clarify such findings locally. Furthermore, local pollution control efforts are often juxtaposed against more seemingly immediate economic concerns in poor communities. OBJECTIVES: The present commentary is a call to action for the evaluation of potentially hazardous elements as potential risk indicators and/or factors of common noncommunicable diseases in the Caribbean. DISCUSSION: Findings from Jamaican studies have identified exposure to potentially hazardous elements (PHE) via water, food, and other anthropogenic activities to the detriment of the resident population. Several attempts have been made to abate toxic metal exposure in children with relative success. However, high levels of PHE have been noted in vulnerable populations such as patients with hypertension, diabetes mellitus and chronic kidney disease. Currently, there is low priority towards infrastructure building within the Caribbean region that would promote and sustain long term monitoring and better inform environmental polices impacting chronic diseases. CONCLUSIONS: Further investigations are needed to clarify the role that PHE play in increasing the risk or progression of non-communicable diseases, especially in vulnerable groups. COMPETING INTERESTS: The authors declare no competing financial interests.

Mercury Exposure Associated with Use of Skin Lightening Products in Jamaica.

BACKGROUND: Skin bleaching is a major health concern among Jamaicans. A common ingredient in skin lightening products is mercury. Mercury is a toxic substance that can cause damage to the gastrointestinal tract, nervous system and kidneys. OBJECTIVE: The objectives of this study were to use different analytical techniques to measure mercury concentrations in popular skin lightening products used in Jamaica and to assess individual levels of mercury exposure based on product usage. METHODS: Sixty skin lightening products were purchased from different vendors across various locations in Jamaica. Each product was initially screened for mercury using a portable handheld energy dispersive X-ray fluorescence (XRF) analyzer. In addition, 25 out of 60 products were further measured using cold vapor atomic absorption spectroscopy (CVAAS). Questionnaires were distributed to users of skin lightening products to determine their usage patterns. RESULTS: Six products had mercury concentrations above the United States Food and Drug Administration (FDA) allowable limit of 1 ppm, of which three products contained alarmingly high concentrations (i.e. > 400 ppm). The majority of products (57 out of 60) had mercury concentrations below 10 ppm. The mercury concentrations in skin lightening products ranged from 0.05 ppm to 17,547 ppm. In our sample, 51% of women and 49% of men used skin products more than once per day. CONCLUSIONS: On average, creams contained more mercury than lotions and soaps. Individuals who use skin lightening products in Jamaica may be at risk for high mercury exposure, as some popular products were found to have mercury concentrations above the allowable limit. COMPETING INTERESTS: The authors declare no competing financial interests.

Risk-Benefit Assessment for Total Mercury, Arsenic, Selenium, and Omega-3 Fatty Acids Exposure from Fish Consumption in Jamaica.

Fish is important in the traditional diet of Jamaicans, and the fishing industry contributes to social and economic development, as well as food security in Jamaica. However, there are associated health risks from contaminant exposure. The aim of this paper was to use risk-benefit analysis methods to determine the best fish species for consumption. Composite samples consisting of 14 fish species were collected from major fishing villages in 2016 and measured for total mercury, arsenic, selenium, and omega-3 fatty acids (EPA and DHA). Food frequency questionnaires were randomly distributed to 400 participants from different locations on the island. Participants were asked to identify the types of fish, portion size, and the frequency of consumption. An estimate of their weight was also recorded. Total mercury concentrations in fish samples ranged from 0.003 to 0.215 µg/g. The range of arsenic concentrations was 0.11 to 7.8 µg/g. The range of selenium concentrations was 0.302 µg/g to 1.08 µg/g. The mean omega-3 fatty acid concentration was 123.1 ± 93.6 mg/100 g. The fish consumption rates range from 3.2 to 1132.8 g/day. Cod fish was the most consumed species at 23.2 g/day. Four risk-benefit analysis methods were able to recommend four fish species that were best for consumption based on the levels of mercury, arsenic, selenium, and omega-3 fatty acids. They were doctorfish, parrotfish, snappers, and cod fish. The results of this study concluded that there was a low risk of mercury exposure from fish consumed in Jamaica.

Bioaccumulation of cadmium in potato tuber grown on naturally high levels cadmium soils in Jamaica.

Jamaican soils have been reported to have naturally high level of cadmium (Cd), and its bioaccumulation in edible crops is of great concern for farmers, stakeholders, and public health authorities. The aim of this study was to determine the levels of Cd in soils in Jamaica and its bioaccumulation in potato tubers, and to determine the dominant soil factors influencing this bioaccumulation in potato. In addition, other soil factors were investigated such pH, electric conductivity (EC), cation exchange capacity (CEC), texture, organic matter content (OMC), and soil zinc (Zn) concentration. The soils' pH and Zn concentration were found to be the dominant factors influencing Cd accumulation in potato tubers, and this was confirmed by using a step-wise multiple regression analysis with the soil factors and tuber Cd (P < 0.05). With soil Cd ranging between 0.05 and 62.3 mg kg-1 and tuber Cd ranging between 0.01 and 0.22 mg kg-1 fresh weight, the bioaccumulation factor (BCF) of Cd in potato tuber gave a precise assessment of the influence of soil variables on Cd accumulation in potato tuber. The Cd concentration in potato tubers was found 50% higher than that recommended by the World Health Organization (WHO) regulation for potatoes (0.05 mg kg-1 fresh weight), and therefore, this should raise real concerns about the human health risk in Jamaica.

Role of Toxic Elements in Chronic Kidney Disease.

BACKGROUND: The kidney is central to many complex pathways in the body and kidney injury can precipitate multiple negative clinical outcomes. The resultant effect on nutrition and elemental body burden is bi-directional, confounding the very complex pathways that maintain homeostasis. These elemental changes themselves increase the risk of nutritional and biochemical disturbances. OBJECTIVES: The aim of the present study was to describe how toxic elements interface with complications of chronic kidney disease (CKD). METHODS: The present review included studies focusing on the molecular mechanisms induced by exposure to elements with known nephrotoxic effects and associated health complications in CKD patients. DISCUSSION: Many non-essential elements have nephrotoxic activity. Chronic injury can involve direct tubular damage, activation of mediators of oxidative stress, genetic modifications that predispose poor cardiovascular outcomes, as well as competitive uptake and element mobilization with essential elements, found to be deficient in CKD. Cardiovascular disease is the most common cause of mortality among CKD patients. Oxidative stress, a common denominator of both deficient and excess element body constitution, underlies many pathological derivatives of chronic kidney disease. Bone disorders, hematological dysfunction and dysregulation of acid-base balance are also prevalent in kidney patients. The largest contribution of toxic element body burden results from environmental exposure and lifestyle practices. However, standard medical therapies may also potentiate toxic element accumulation and re-injury of vulnerable tissue. CONCLUSIONS: For CKD patients, the cumulative effect of toxic elements persists throughout the disease and potentiates complications of CKD. Medical management should be coordinated between a medical team, dietitians and clinical researchers to mitigate those harmful effects. COMPETING INTERESTS: The authors declare no competing financial interests.

Factors associated with mercury levels in human placenta and the relationship to neonatal anthropometry in Jamaica and Trinidad & Tobago.

The aim of this study was to investigate the mercury levels in human placenta and its relationship to neonatal anthropometry for a group of selected pregnant women in Kingston and Manchester in Jamaica and St. Joseph in Trinidad & Tobago. The participants were interviewed on their fish intake. Neonatal anthropometric data were also recorded. The placental mercury concentrations ranged from 0.64±0.5µg/kg to 1.4±0.6µg/kg. The most significant associated factor for prenatal mercury exposure was maternal fish intake. Those pregnant women who regularly ate shark recorded the highest placenta mercury concentrations. Their neonates also had slightly smaller mean head circumference and lower birth weight. The mean placental mercury concentrations in this study were found to be lower than the literature values. Therefore it was difficult to detect any significant changes in neonatal anthropometry. This type of study can contribute to the extent of mercury exposure in the region.

Assessment of Radon Levels in Drinking Water Wells in St. Catherine, Jamaica.

BACKGROUND: Radon is a known carcinogen and contaminant in drinking water wells, but is not monitored in drinking water quality programs in Jamaica. OBJECTIVE: The present study was conducted to obtain radon data in local drinking water and evaluate potential health risks. The data will contribute to determining the level of compliance to public health criteria for radon and to develop a monitoring program based on the identified risks. METHODS: This study assesses the concentration of radon in 22 drinking water wells in the parish of St. Catherine, Jamaica. Samples were collected for radon, with 12 other measurements gathered including pH, conductivity, TDS, alkalinity, hardness, phosphates, nitrates, chloride, sulfates, turbidity, well depth and geological features. The data were analyzed for compliance to international limits and association with geological and other parameters. RESULTS: The average radon level was 18 Bq/L ± 2 Bq/L and varied from a low of 11 Bq/L ± 1 Bq/L to a high of 41 Bq/L ± 1 Bq/L. There was a positive correlation between radon levels and both alkalinity and turbidity. No relationship of any significance, however, was identified with the other physicochemical parameters. All the study results fell within the European Union (EU) limit of 100 Bq/L, and well within the United States Environmental Protection Agency (USEPA) limit of 147 Bq/L. Most of the wells in this parish have radon levels exceeding the proposed USEPA limit of 11 Bq/L. The proposed limits are intended to support radon mitigation programs to manage radon in air. No limits are provided in the newest edition of the World Health Organization's (WHO) Guidelines for Safe Drinking Water Quality. CONCLUSIONS: Most wells in the study area met existing international limits. Almost all, however, did not meet the proposed USEPA limit for locations without radon mitigation programs. This indicates the need to establish national screening levels for radon, consistent with WHO and USEPA recommendations.

Assessment of fish consumption and mercury exposure among pregnant women in Jamaica and Trinidad & Tobago.

BACKGROUND: Fish is an essential and traditional element in the diet of most Caribbean people. However it also contains methylmercury which can have severe effects on fetal neurodevelopment. The objective of this study was to assess the fish intake of a selected group of pregnant women from Jamaica and Trinidad & Tobago and evaluate prenatal mercury exposure, using the placenta as a biomarker. METHOD: Food frequency questionnaires and placental samples were obtained from participating parturients at the time of delivery at the University Hospital of the West Indies in Kingston, Jamaica (N = 100, from November 2012 to March 2013) and the Mt Hope Women's hospital in St Joseph, Trinidad & Tobago (N = 30, in June 2015). The participants were asked to identify the species of fish and the frequency of consumption. Placental samples were analysed for mercury using cold vapour atomic absorption. RESULTS: The fish consumption preferences for pregnant women, varies based on the marine fish catch production of each country. The main fish species that contributed to the highest estimated methylmercury exposure in Jamaica and Trinidad & Tobago were cod and shark, respectively. There was a weak association between maternal fish intake and placental mercury concentrations. The mean placental mercury concentrations in Jamaica and Trinidad & Tobago were 0.74 ± 0.5 µg/kg and 1.46 ± 0.6 µg/kg, wet weight respectively. CONCLUSION: The results from this study showed an influence of Caribbean fish intake preferences on mercury exposure and thus a recommendation for continuous bio-monitoring for public health purposes.