Tag Archives: health effects

Skeletal fluorosis, Sri Lanka

Hewavithana PB, Jayawardhane WM, Gamage R, Goonaratna C. Skeletal fluorosis in Vavuniya District: an observational study. The Ceylon medical journal. 2018 Sep 30;63(3):139-142.

BACKGROUND: The WHO recommended safe upper limit for fluoride in drinking water is 1.5 mg/l. Groundwater sources in many parts of Sri Lanka often exceed this limit. The high fluoride content of groundwater and high environmental temperatures in Vavuniya District predispose to pre-skeletal fluorosis and skeletal fluorosis in adults.

OBJECTIVES: To identify residents of Vavuniya District with clinical features of pre-skeletal and skeletal fluorosis; to describe their clinical, biochemical and radiographic features; to determine the fluoride content of blood and urine in individuals with established diagnoses, and of their drinking water.

METHODS: In 98 volunteers we detected 60 with clinical features of pre-skeletal and skeletal fluorosis. Clinical examination, biochemical and radiographic investigations were performed. Forty four with confounding factors were excluded. The balance 16 had radiographic investigation for fluoride bone disease, and assessment of clinical features for pre-skeletal fluorosis. The radiographic criteria of skeletal fluorosis were trabecular haziness, osteosclerosis, osteophytes, cortical thickening and ligamentous or muscle attachment ossification. All 16 had “spot” samples of 15 ml of venous blood taken for biochemical tests and fluoride estimation; and 30 ml of urine, and water from 16 dug wells for fluoride.

RESULTS: The 16 selected (11 males) had BMI between 20.6 and 31.9 kg/m2, and were between 22 and 84 years (x̅ = 59.9 + 20.4). They used water from domestic dug wells for drinking. All had adequate renal function. All serum and urine samples had raised fluoride levels way above the reference ranges for serum (0.02 – 0.18 mg/l) and urine (0.6 – 2.0 mg/l). The 16 water samples showed a mean fluoride content of 2.90 +0.93 mg/l.

INTERPRETATION: In a cohort of 60 individuals in Vavuniya with symptoms suggestive of skeletal fluoride toxicity, 6 had skeletal fluorosis, 10 had pre-skeletal fluorosis, and groundwater sources had fluoride levels much higher than WHO recommended upper limit for drinking water. Residents in Vavuniya are predisposed to pre-skeletal and skeletal fluorosis. All 16 had been misdiagnosed as various types of arthritis.

Recent study attempts to “prop-up” community fluoridation advocacy

Spencer AJ, Do LG, Ha DH. Contemporary evidence on the effectiveness of water fluoridation in the prevention of childhood caries. Community Dent Oral Epidemiol. 2018 Aug;46(4):407-415. doi: 10.1111/cdoe.12384. 

BACKGROUND: Water fluoridation’s effectiveness has been reaffirmed by systematic reviews. However, most of the included nonrandomised controlled before and after studies were conducted pre-1975. Opportunity for such studies is limited in a steady state of community fluoridation programmes. As an alternative for evidence to support or refute the effectiveness of water fluoridation, this study used data from a recent national child oral health study to examine associations between lifetime exposure to fluoridated water (%LEFW) and childhood caries.

METHODS: A population-based study of child oral health in Australia was conducted in 2012-2014, using complex sampling and weighting procedures. Parents provided detailed household information and children underwent oral epidemiological examination by trained examiners. Residential history from birth was used to calculate %LEFW. Caries prevalence (dmfs/DMFS>0) and experience (dmfs/DMFS) in both primary (age 5-8) and permanent dentitions (age 9-14) were estimated. Socioeconomic factors that were significantly different by %LEFW were then used as covariates in multivariable log-Poisson regression models for each caries outcome by %LEFW.

RESULTS: A total of 24 664 children had complete data. Caries prevalence and experience were higher among 5-8-year-old children with lower %LEFW (46.9%; 4.27 surfaces) than those with 100%LEFW (31.5%; 1.98 surfaces) and for the 9-14-year-old children with lower %LEFW (37.0%; 1.34 surfaces) than those with 100%LEFW (25.0%; 0.67 surfaces). In the multivariable models, the prevalence ratios for primary and permanent caries were significant for the two lower exposure groups against the 100%LEFW group. Similarly, the mean ratios for primary dmfs were significant for all three lower exposure groups and for permanent DMFS were significant for the two lower exposure groups against the 100%LEFW group. Mean ratios for the 0%LEFW compared to the 100%LEFW group were 2.10 (1.83-2.40) for dmfs and 1.82 (1.57-2.10) for DMFS.

CONCLUSION: Analysis of contemporary data representative of the Australian child population found consistent associations between %LEFW and childhood caries, which persisted when socioeconomic differences were adjusted across exposure groups, supporting the continued effectiveness of water fluoridation.

Heat-mortality impacts declined over the past decades

Ana M. Vicedo-Cabrera et al. A multi-country analysis on potential adaptive mechanisms to cold and heat in a changing climate Environment International Volume 111, February 2018, Pages 239-246


Temporal variation of temperature-health associations depends on the combination of two pathways: pure adaptation to increasingly warmer temperatures due to climate change, and other attenuation mechanisms due to non-climate factors such as infrastructural changes and improved health care. Disentangling these pathways is critical for assessing climate change impacts and for planning public health and climate policies. We present evidence on this topic by assessing temporal trends in cold- and heat-attributable mortality risks in a multi-country investigation.


Trends in country-specific attributable mortality fractions (AFs) for cold and heat (defined as below/above minimum mortality temperature, respectively) in 305 locations within 10 countries (1985–2012) were estimated using a two-stage time-series design with time-varying distributed lag non-linear models. To separate the contribution of pure adaptation to increasing temperatures and active changes in susceptibility (non-climate driven mechanisms) to heat and cold, we compared observed yearly-AFs with those predicted in two counterfactual scenarios: trends driven by either (1) changes in exposure-response function (assuming a constant temperature distribution), (2) or changes in temperature distribution (assuming constant exposure-response relationships). This comparison provides insights about the potential mechanisms and pace of adaptation in each population.


Heat-related AFs decreased in all countries (ranging from 0.45–1.66% to 0.15–0.93%, in the first and last 5-year periods, respectively) except in Australia, Ireland and UK. Different patterns were found for cold (where AFs ranged from 5.57–15.43% to 2.16–8.91%), showing either decreasing (Brazil, Japan, Spain, Australia and Ireland), increasing (USA), or stable trends (Canada, South Korea and UK). Heat-AF trends were mostly driven by changes in exposure-response associations due to modified susceptibility to temperature, whereas no clear patterns were observed for cold.


Our findings suggest a decrease in heat-mortality impacts over the past decades, well beyond those expected from a pure adaptation to changes in temperature due to the observed warming. This indicates that there is scope for the development of public health strategies to mitigate heat-related climate change impacts. In contrast, no clear conclusions were found for cold. Further investigations should focus on identification of factors defining these changes in susceptibility.

Presumption of “safety” drives fluoridation study interpretation

Slade GD, Grider WB, Maas WR, Sanders AE. Water Fluoridation and Dental Caries in U.S. Children and Adolescents. J Dent Res. 2018 Sep;97(10):1122-1128. doi: 10.1177/0022034518774331.

Fluoridation of America’s drinking water was among the great public health achievements of the 20th century. Yet there is a paucity of studies from the past 3 decades investigating its dental health benefits in the U.S. This cross-sectional study sought to evaluate associations between availability of community water fluoridation (CWF) and dental caries experience in the U.S. child and adolescent population. County-level estimates of the percentage of population served by CWF (% CWF) from the Centers for Disease Control and Prevention’s Water Fluoridation Reporting System were merged with dental examination data from 10 y of National Health and Nutrition Examination Surveys (1999 to 2004 and 2011 to 2014). Dental caries experience in the primary dentition (decayed and filled tooth surfaces [dfs]) was calculated for 7,000 children aged 2 to 8 y and in the permanent dentition (decayed, missing, and filled tooth surfaces [DMFS]) for 12,604 children and adolescents aged 6 to 17 y. Linear regression models estimated associations between % CWF and dental caries experience with adjustment for sociodemographic characteristics: age, sex, race/ethnicity, rural-urban location, head-of-household education, and period since last dental visit. Sensitivity analysis excluded counties fluoridated after 1998. In unadjusted analysis, caries experience in the primary dentition was lower in counties with ≥75% CWF (mean dfs = 3.3; 95% confidence limit [CL] = 2.8, 3.7) than in counties with <75% CWF (mean dfs = 4.6; 95% CL = 3.9, 5.4), a prevented fraction of 30% (95% CL = 11, 48). The difference was also statistically significant, although less pronounced, in the permanent dentition: mean DMFS (95% CL) was 2.2 (2.0, 2.4) and 1.9 (1.8, 2.1), respectively, representing a prevented fraction of 12% (95% CL = 1, 23). Statistically significant associations likewise were seen when % CWF was modeled as a continuum, and differences tended to increase in covariate-adjusted analysis and in sensitivity analysis. These findings confirm a substantial caries-preventive benefit of CWF for U.S. children and that the benefit is most pronounced in primary teeth.

Exposure routes and health effects of microcystins

Massey IY, Yang F, Ding Z, Yang S, Guo J, Tezi C, Al-Osman M, Kamegni RB, Zeng W. Exposure Routes and Health Effects of Microcystins on Animals and Humans: A Mini-review. Toxicon. 2018 Jul 9. pii: S0041-0101(18)30306-4. doi: 10.1016/j.toxicon.2018.07.010.

Microcystins (MCs) pollution has quickly risen in infamy and has become a major problem to public health worldwide. MCs are a group of monocyclic hepatotoxic peptides, which are produced by some bloom-forming cyanobacteria in water. More than 100 different MCs variants posing a great threat to animals and humans due to their potential carcinogenicity have been reported. To reduce MCs risks, the World Health Organization has set a provisional guideline of 1 µg/L MCs in human’s drinking water. This paper provides an overview of exposure routes of MCs into the human system and health effects on different organs after MCs exposure including the liver, intestine, brain, kidney, lung, heart and reproductive system. In addition, some evidences on human poisoning and deaths associated with MCs exposure are presented. Finally, in order to protect human life against the health threats posed by MCs, this paper also suggests some directions for future research that can advance MCs control and minimize human exposure to MCs.

Increase in Malaria deaths a global warming myth

“The Our World in Data recently updated a report, originally published in 2015. According to it, WHO data showed deaths from malaria have fallen by 48% since 2000.” click here and here

Did Lancet publish fake health arguments?

Just wondering….

Mikko Paunio Sacrificing the Poor: The Lancet on pollution Global Warming Policy Foundation, 2018.

“Executive summary

The Lancet, one of the world’s leading medical journals, recently published two long commissioned reports, timed to coincide with 23rd Conference of Parties to the UN Framework Convention on Climate Change and the third UN Environment Assembly. The journal’s aim was to boost climate change mitigation and enhance a ‘Pollution free World’ initiative in the name of public health. This paper gives examples of the biased, misleading and false health-based arguments that are made in these reports. The main conclusions of the Lancet reports – widely disseminated by the mass media – were as follows: • that a huge global mortality burden is attributable to industrial pollution • that a key to gaining health co-benefits of climate change mitigation is to introduce a moratorium on construction of coal-fired power plants. Both conclusions are false. To arrive at them, the authors of both reports have hidden the benefits of the comprehensive institutional environmental health protection action – based on hygiene principles – that helped to eradicate malnutrition from today’s richer nations in the period after the Second World War. The authors of both reports have also, by not quoting (or by misquoting) a game-changing article published inNature, advanced the false argument that industrial development is to blame for much disease and mortality around the world, and in particular in the developing world. The Lancet report declared that 9 million deaths each year are attributable to ‘pollution’. However, almost all these deaths are a function of underdevelopment. Pervasive fecal pollution, including animal manure, is the root cause of mass malnutrition among 800 million people, causing repeated bouts of diarrhea that often leave children permanently malnourished or stunted. Malnutrition then makes people especially vulnerable to the detrimental effects of indoor and outdoor air pollution from the domestic burning of wood, other forms of biomass, and coal for heating and cooking. The Lancet pollution report mentions the link, but shamefully fails to deal with the implications. Neither of the Lancet reports is of much help in putting the vitally important but totally neglected subject of institutional environmental health action on the sustainable development agenda. Although the authors of the pollution report have sought to take the moral high ground by quoting the Pope’s Laudato Si encyclical on the environment, both of the reports are immoral, and gross distortions of public health science and the historical achievements of health protection.” click here