Review on the problem of sanitary-epidemiological welfare of the population in the Siberian Federal District (SFD) was conducted based on literature data and authors own research in the period of 2002-2014. Authors provided broad information on the health and demographic and epidemiological characteristics of SFD population. SFD in comparison with other regions of the Russian Federation overcomes one of the most adverse situations including mortality rates from external causes. SFD population’s infectious and somatic morbidity rates were analyzed. Analysis demonstrated that the situation relating to priority epidemiologically and socially important infections (HIV-infection, parenteral viral hepatitis, tuberculosis etc.) on the territory of the SFD remains tense. Authors provided information on the increase in the level of the actual for Siberian regions natural-foci tick-borne infections. Detailed analysis for the environment anthropogenic pollution impact for the epidemic, infectious and vaccine induced processes. Authors suggest that anthropogenic (biological) environmental pollution is one of the most important factors influencing the epidemiological welfare of the Siberian population. A new strategic direction in epidemiological research associated with the problem of comorbid diseases is planned.
Little is known about the prevalence of asthma, allergic rhinitis, eczema and allergies among Canadian Inuit children, especially those living in the arctic and subarctic areas.
A cross-sectional study among Grade 1 students attending schools in Iqaluit, the capital of Nunavut, was conducted during the 2015/2016 school year. We used the International Study of Allergy and Asthma in Children questionnaire with added questions relevant to the population. In addition, skin prick tests were conducted to test for sensitization to common food and environmental allergens.
The prevalence of current asthma was 15.9% (> 2:1 males) with the highest prevalence among those with any non-Inuit heritage at 38.5%. The prevalence of current and past allergic rhinitis was 6.8%, also predominant among males, with the lowest prevalence among the mixed ethnicity. Home crowdedness was inversely related to past asthma. Being ever outside Nunavut was associated with higher prevalence of current and past asthma. No statistically significant relationship was found with passive smoking or exclusive breast feeding during the first 4 months of life. The current eczema prevalence was 20.5%, with the highest prevalence recorded among the Inuit at 25% compared to 15.4% among the mixed ethnicity and 14.3% among the non-Inuit. We noted a high rate of sensitization to cat at 26.7% while absent sensitization to other common inhalant allergens.
Variations in the prevalence and risk factors of asthma, allergic rhinitis and eczema among different ethnicities living at the same subarctic environment may be related to genetic, gene-environment interaction and/or lifestyle factors that require further investigation.
Ecological risks (ERs) of pollutants are typically assessed using species sensitivity distributions (SSDs), based on effect concentrations obtained from bioassays with unknown representativeness for field conditions. Alternatively, monitoring data relating breeding success in bird populations to egg concentrations may be used. In this study, we developed a procedure to derive SSDs for birds based on field data of egg concentrations and reproductive success. As an example, we derived field-based SSDs for p, p'-DDE and polychlorinated biphenyls (PCBs) exposure to birds. These SSDs were used to calculate ERs for these two chemicals in the American Great Lakes and the Arctic. First, we obtained field data of p, p'-DDE and PCBs egg concentrations and reproductive success from the literature. Second, these field data were used to fit exposure-response curves along the upper boundary (right margin) of the response's distribution (95th quantile), also called quantile regression analysis. The upper boundary is used to account for heterogeneity in reproductive success induced by other external factors. Third, the species-specific EC10/50s obtained from the field-based exposure-response curves were used to derive SSDs per chemical. Finally, the SSDs were combined with specific exposure data for both compounds in the two areas to calculate the ER. We found that the ERs of combined exposure to these two chemicals were a factor of 5-35 higher in the Great Lakes compared to Arctic regions. Uncertainty in the species-specific exposure-response curves and related SSDs was mainly caused by the limited number of field exposure-response data for bird species. With sufficient monitoring data, our method can be used to quantify field-based ecological risks for other chemicals, species groups, and regions of interest.
Owing to the shared embryonic origin, defects in development of optic nerves are often seen in conjunction with defects affecting the surrounding brain and pituitary gland. Optic nerve hypoplasia (ONH) and septo-optic dysplasia (SOD) represent a clinical spectrum associated with visual, pituitary and severe central nervous system structural abnormalities (SODplus). Based on changing clinical patterns, our primary objective was to examine trends in annual incidence of ONH/SOD and geographical clustering in Manitoba.
This was a retrospective 1996 to 2015 chart review with extraction of anthropometric measures, radiologic findings, parental characteristics, endocrinopathies and neurologic symptoms from all involved in care. Postal codes were used to assign map co-ordinates and identify relevant census-based deprivation indices.
Ninety-three children were identified in our catchment area; Poisson regression confirmed a striking 1.11-fold annual increase (95% confidence interval 1.07 to 1.16) or ~800% over two decades. The annual incidence (averaged 2010 to 2014 chart data) reached 53.3 per 100,000, affecting 1 in 1875 live births. Most (~55%) had SODplus. Common presenting features were hypoglycemia, nystagmus, seizures and developmental delay; 40% had hormone deficiencies; 80% had reduced visual acuity, typically bilateral. Many were premature with young, primiparous mothers. Unhealthy maternal lifestyles and severe material deprivation were noted. There was disproportionate clustering in individuals from Northern Manitoba at three times the average provincial rate.
We noted a dramatic rise in the annual incidence of ONH/SOD, which was strongly associated with poverty and northern communities. The pattern was consistent with environmental or nutritional etiologies. Many children were severely affected with increased morbidity and health care burdens.
Cites: J AAPOS. 1999 Feb;3(1):26-32 PMID 10071898
Cites: Int J Pediatr Endocrinol. 2015;2015(1):8 PMID 25878671
The aim of this paper was to conduct pilot-scale column tests on an alternative treatment filter designed for the treatment of highway stormwater in cold climates. The study evaluated adsorption performance of the filter with regard to the four most commonly found metals (Cu, Ni, Pb, and Zn) in highway stormwater. An alternative method was used to estimate the operational life of the filter from the adsorption test data without a breakthrough under high hydraulic loads. The potential environmental impact of the filter was assessed by comparing desorption test data with four different environmental quality standards. The proposed filter achieved high adsorption (over 90%) of the target metals. The comparisons of desorption and leaching data with the environmental standards indicated that iron-oxide/bottom ash was non-hazardous, reusable and without serious environmental risks. The operational life and filter dimensions were highly dependent on rainfall depth, which indicated that the filter design would have to be adapted to suit the climate. To fully appreciate the performance and environmental aspects, the filter unit should be tested in the field and the testing should explicitly include ecotoxicological and life cycle impacts.
Division of Risk Management, Department of Environmental and Life Sciences, Karlstad University, Karlstad, Sweden; Centre for Public Safety, Karlstad University, Sweden. Electronic address: email@example.com.
Residential fires represent the largest category of fatal fires in Sweden. The purpose of this study was to describe the epidemiology of fatal residential fires in Sweden and to identify clusters of events.
Data was collected from a database that combines information on fatal fires with data from forensic examinations and the Swedish Cause of Death-register. Mortality rates were calculated for different strata using population statistics and rescue service turnout reports. Cluster analysis was performed using multiple correspondence analysis with agglomerative hierarchical clustering.
Male sex, old age, smoking, and alcohol were identified as risk factors, and the most common primary injury diagnosis was exposure to toxic gases. Compared to non-fatal fires, fatal residential fires more often originated in the bedroom, were more often caused by smoking, and were more likely to occur at night. Six clusters were identified. The first two clusters were both smoking-related, but were separated into (1) fatalities that often involved elderly people, usually female, whose clothes were ignited (17% of the sample), (2) middle-aged (45-64years old), (often) intoxicated men, where the fire usually originated in furniture (30%). Other clusters that were identified in the analysis were related to (3) fires caused by technical fault, started in electrical installations in single houses (13%), (4) cooking appliances left on (8%), (5) events with unknown cause, room and object of origin (25%), and (6) deliberately set fires (7%).
Fatal residential fires were unevenly distributed in the Swedish population. To further reduce the incidence of fire mortality, specialized prevention efforts that focus on the different needs of each cluster are required.
Cooperation between various societal functions, e.g. rescue services, elderly care, psychiatric clinics and other social services, with an application of both human and technological interventions, should reduce residential fire mortality in Sweden.
Cell phone use during pregnancy is a public health concern. We investigated the association between maternal cell phone use in pregnancy and child's language, communication and motor skills at 3 and 5 years.
This prospective study includes 45,389 mother-child pairs, participants of the MoBa, recruited at mid-pregnancy from 1999 to 2008. Maternal frequency of cell phone use in early pregnancy and child language, communication and motor skills at 3 and 5 years, were assessed by questionnaires. Logistic regression was used to estimate the associations.
No cell phone use in early pregnancy was reported by 9.8% of women, while 39%, 46.9% and 4.3% of the women were categorized as low, medium and high cell phone users. Children of cell phone user mothers had 17% (OR = 0.83, 95% CI: 0.77, 0.89) lower adjusted risk of having low sentence complexity at 3 years, compared to children of non-users. The risk was 13%, 22% and 29% lower by low, medium and high maternal cell phone use. Additionally, children of cell phone users had lower risk of low motor skills score at 3 years, compared to children of non-users, but this association was not found at 5 years. We found no association between maternal cell phone use and low communication skills.
We reported a decreased risk of low language and motor skills at three years in relation to prenatal cell phone use, which might be explained by enhanced maternal-child interaction among cell phone users. No evidence of adverse neurodevelopmental effects of prenatal cell phone use was reported.
Department of Environmental Exposure and Epidemiology, Domain of Infection Control and Environmental Health, Norwegian Institute of Public Health, P.O. Box 4404, Nydalen, NO-0403, Oslo, Norway. AnneLise.Brantsaeter@fhi.no.
Preterm delivery increases the risk of neonatal morbidity and mortality. Studies suggest that maternal diet may affect the prevalence of preterm delivery. The aim of this study was to assess whether maternal intakes of seafood and marine long chain n-3 polyunsaturated fatty acids (LCn-3PUFA) from supplements were associated with preterm delivery.
The study population included 67,007 women from the Norwegian Mother and Child Cohort Study. Maternal food and supplement intakes were assessed by a validated self-reported food frequency questionnaire in mid-pregnancy. Information about gestational duration was obtained from the Medical Birth Registry of Norway. We used Cox regression to estimate hazard ratios (HR) with 95% confidence intervals (CI) for associations between total seafood, lean fish, fatty fish, and LCn-3PUFA intakes and preterm delivery. Preterm was defined as any onset of delivery before gestational week 37, and as spontaneous or iatrogenic deliveries and as preterm delivery at early, moderate, and late preterm gestations.
Lean fish constituted 56%, fatty fish 34% and shellfish 10% of seafood intake. Any intake of seafood above no/rare intake (>5 g/d) was associated with lower prevalence of preterm delivery. Adjusted HRs were 0.76 (CI: 0.66, 0.88) for 1-2 servings/week (20-40 g/d), 0.72 (CI: 0.62, 0.83) for 2-3 servings/week (40-60 g/d), and 0.72 (CI: 0.61, 0.85) for =3 servings/week (>60 g/d), p-trend
We tested the association between alcohol use disorder (AUD) and divorce; estimated the genetic and environmental influences on divorce; estimated how much genetic and environmental influences accounted for covariance between AUD and divorce; and estimated latent genetic and environmental correlations between AUD and divorce. We tested sex differences in these effects.
We identified twin and sibling pairs with AUD and divorce information in Swedish national registers. We described the association between AUD and divorce using tetrachorics and used twin and sibling models to estimate genetic and environmental influences on divorce, on the covariance between AUD and divorce and the latent genetic and environmental correlations between AUD and divorce.
A total of 670?836 individuals (53% male) born 1940-1965.
Life-time measures of AUD and divorce.
AUD and divorce were related strongly (males: rtet = +0.44, 95% CI = 0.43, 0.45; females rtet = +0.37, 95% CI = 0.36, 0.38). Genetic factors accounted for a modest proportion of the variance in divorce (males: 21.3%, 95% CI = 7.6, 28.5; females: 31.0%, 95% CI = 18.8, 37.1). Genetic factors accounted for most of the covariance between AUD and divorce (males: 52.0%, 95% CI = 48.8, 67.9; females: 53.74%, 95% CI = 17.6, 54.5), followed by non-shared environmental factors (males: 45.0%, 95% CI = 37.5, 54.9; females: 41.6%, 95% CI = 40.3, 60.2). Shared environmental factors accounted for a negligible proportion of the covariance (males: 3.0%, 95% CI = -3.0, 13.5; females: 4.75%, 95% CI = 0.0, 6.6). The AUD-divorce genetic correlations were high (males: rA = +0.76, 95% CI = 0.53, 0.90; females +0.52, 95% CI = 0.24, 0.67). The non-shared environmental correlations were modest (males: rE = +0.32, 95% CI = 0.31, 0.40; females: +0.27, 95% CI = 0.27, 0.36).
Divorce and alcohol use disorder are correlated strongly in the Swedish population, and the heritability of divorce is consistent with previous studies. Covariation between AUD and divorce results from overlapping genetic and non-shared environmental factors. Latent genetic and non-shared environmental correlations for alcohol use disorder and divorce are high and moderate.
The 2011 Richardson wildland mega-fire in the Athabasca Oil Sands Region (AOSR) in northern Alberta, Canada had large effects on air quality. At a receptor site in the center of the AOSR ambient PM2.5, O3, NO, NO2, SO2, NH3, HONO, HNO3, NH4+ and NO3- were measured during the April-August 2011 period. Concentrations of NH3, HNO3, NO2, SO2 and O3 were also monitored across the AOSR with passive samplers, providing monthly summer and bi-monthly winter average values in 2010, 2011 and 2012. During the fire, hourly PM2.5 concentrations >450µgm-3 were measured at the AMS 1 receptor site. The 24-h National Ambient Air Quality Standard (NAAQS) of 35µgm-3 and the Canada Wide Standard (CWS) of 30µgm-3 were exceeded on 13days in May and 7days in June. During the fire emission periods, sharp increases in NH3, HONO, HNO3, NH4+, NO3- and total inorganic reactive N concentrations occurred, all closely correlated with the PM2.5 changes. There were large differences in the relative contribution of various N compounds to total inorganic N between the no-fire emission and fire emission periods. While in the absence of fires NO and NO2 dominated, their relative contribution during the fires was ~2 fold smaller, mainly due to increased NH3, NH4+ and NO3-. Concentrations of HONO and HNO3 also greatly increased during the fires, but their contribution to the total inorganic N pool was relatively small. Elevated NH3 and HNO3 concentrations affected large areas of northern Alberta during the Richardson Fire. While NH3 and HNO3 concentrations were not at levels considered toxic to plants, these gases contributed significantly to atmospheric N deposition. Generally, no significant changes in O3 and SO2 concentrations were detected and their ambient concentrations were below levels harmful to human health or sensitive vegetation.
One of the main criteria which determine the possibility of the use of a particular type of ice-melter reagents (IMR) is the degree of their safety for the environment and human health, which is reflected in the establishment of safe doses and concentrations. In this regard, the current area of research is to improve the ecological and epidemiological principles of risk assessment of modern types of anti-icing agents. Currently available data concerning monitoring soil studies and the snow held in various cities of Russia, show that there is a process of accumulation of the main components of IMR - sodium and chlorine ions in the areas related to the roadway. The article is designated a problem of existing methodological approaches to the assessment of the phytotoxic impact in the investigation of anti-icing agents in the laboratory. There was executed the comparative characteristics of the results of the preliminary pilot studies on the phytotoxic properties of IMR under using different substrates for germination of seeds - soil and filter paper. The data obtained are characterized by differences in the degree of phytotoxic action of the same species depending upon ice-melter reagents methodical setting circuit laboratory experiment. As a result, there was shown the imperfection of the existing method of rapid analysis in relation to ice-melter materials (IMM).
Negative trends in incidence rates of children and adolescents of the city of Penza are due to the influence of both environmental factors as well as the educational process. Hygienic trouble in the city of Penza determines air pollution emissions of road transport, as evidenced by the high levels of morbidity rate in children and adolescents. The priorities for the correction factors are conditions and the organization of nutrition, physical education. There are identified the most important lifestyle factors for senior pupils that need the solution.
There was executed the ecologic-hygienic assessment of the distribution of respiratory diseases prevalence in bioclimatic zones of the Primorsky Krai. The aim of the study was a systematic assessment of the impact of ecological-hygienic factors of environment on the distribution of respiratory diseases in adolescents and children of the Primorsky region. As an information database there were used indices of the prevalence of diseases of the respiratory system of the ICD-10 class of the official statistical report forms for the period of2000-2013 and the parameters of the environment offactor modules (6 - socio-sanitary, 5 - environmental). The numerical values of modules offactors were determined according to a specially developed scoring scale. The study of the prevalence was carried out with the use of a classical method of data analysis - descriptive statistics, Chi-square criteria. By means of the method of regression analysis from the SPSS package software there was established the relationship of environmental factors and the level of the prevalence of diseases, and were calculated values of the factor loadings influencing on the morbidity rate of children and adolescents. The study revealed that in the structure of morbidity diseases of the respiratory system account of 39% in adolescents, 61% - in children. Constructed predictive models describe the trend of the increasing in the prevalence in adolescents and children. Over the past 15 years, the level of respiratory diseases morbidity rate increased by 46.1%. It is established that the prevalence of respiratory diseases in children and adolescents from various districts of the Primorsky territory depends on the features of the bioclimatic zones and the degree of sanitary-hygienic situation, as well as combinations of parameters that form these zones; the highest cumulative level of the prevalence is observed in the bioclimatic zone of the coast, that is caused by the various degree of the impact of biotropic factors of environment; The prevalence of diseases of respiratory system is mainly affected by bioclimatic factors: residence in an area of high humidity, temperature swings, movements of air masses in combination with air pollution.
The realization of the package of measures directed at the consecutive decrease of the negative effect of hazardous chemical and biological factors on the population and environment to the acceptable risk level stipulates the development of standard legal regulation in the field of ensuring the chemical and biological safety. For this purpose article presents substantiation and conceptual approaches to the creation of legislation in the field of the chemical and biological security of the Russian Federation within the pursued state policy. In determination of conceptual approaches, in the article there are reported: the main idea, the purpose, a subject of legal regulation, the circle of people who will be subjected to the laws, the place offuture laws in the system of current legislation, the provisions of the Constitution of the Russian Federation, the Federal backbone laws of the Russian Federation to realization of which laws are directed, there is given the general characteristic and an assessment of a condition of legal regulation in this field, results of the analysis of the information on the need for correspondence of Russian laws to provision of international treaties, concerning prohibitions of the biological and chemical weapon, safe handling with biological agents and chemicals, and also the development of uniform procedures of ensuring chemical and biological safety. The major aspect in the shaping of the legislation is the global character ofproblems of chemical and biological safety in this connection in article there is indicated the need of rapprochement of rules of law for this area with partners in economic cooperation and integration. Taking into account an orientation of future laws on the decrease in the level of the negative impact of dangerous chemical and biological factors on the population and environment, there are designated medical, social, economic and political consequences of their implementation. There are presented the proposed structure for bills: “About biological safety”, “On Chemical Safety” and “On the National collection of pathogens.
Paramount problems of the development of the assessment of population health risks associated with the chemical exposure in Russia are considered on the ground of critical analysis of reports devoted to methodological issues of the risk assessment and guidelines published since 2010. Causes of the lack in progress of risk assessment are discussed. The information of executed research revealed the significant retardation number of Russian publications devoted to the evidence-based health risk assessment compare to worldwide trend. The analysis of publications according to evidence-based health risk assessment in Russia in 1998 - 2012 demonstrated methodical problems to be leading to the underestimation of the real risk to population’s health. There are demonstrated directions in the renewal of methodology and practice of hygienic standardization on the basis of the risk assessment. The comparative analysis of values of uncertainty factors (modifying factors, conversion factors) used for extrapolation and accepted in different countries and organizations was made. The system of extrapolation coefficients of DNEL (Derive No-Effect Level) is presented. The leading principles of modern toxicology and risk assessment based on strict scientific proofs are showed. Criteria of evidence-based toxicology and risk assessment are presented.Among actual problems which demand their decision there are considered: the assessment of combined action in regulatory toxicology; expansion of spheres of the application of health risk assessment methodology; the improvement ofpreparation and certification of experts in the field of health risk assessment; need of check of dispersion models and their replacement by more modern models; the improvement of exposure assessment with taking into account the international requirements; the assessment of regional exposure factors; expansion of atmospheric air monitoring in all the large cities of Russia.
Research priorities of Alexei Nikolaevich Sysin (1879-1956) were faced to the study of issues of sanitary and epidemiological welfare of Russia. World- renowned hygienist scientist was the one of the pioneers in the field of general and communal hygiene, epidemiology and disinfection. Not little attention A.N. Sysin paid also to issues of occupational health, together with other scientists he laid the foundation of modern Occupational Health. The victory of the Great October Revolution has set before organizers and medical science scholars, among who was A.N. Sysin, new challenges in dealing with the many complex issues, including occupational health issues. Already in the first months of the new Republic he prepared dozens of directives, regulations and instructions, wrote a large number of draft laws for health services, developed the first regulations on the sanitary supervision of the country enterprises. The leading role in the emergence of many printed newspapers and magazines, books and bulletins on general issues in health, preventive medicine, hygiene, epidemiology, occupational health is belonged to A.N. Sysin. He published more than 250 scientific papers on various aspects of sanitary science: from the problems of epidemics of dangerous infections to the working and living conditions of different enterprises. A. N. Sysin paid a lot of attention to industrial injuries, problems of increscent occupational toxicology, the introduction of newest forms of general and personal protective equipment at the plant, modernization of the industrial equipment, issues of the shortened workday, labor of women and children - all kinds of sanitary measures and improvement of labor and living workers' conditions.
Senior citizens get around, to a large extent, as pedestrians, and safe walking is desirable for senior citizens allowing them to stay mobile, independent and healthy in old age. Senior citizens are over-represented in injury statistics, and fall-related injuries are common. The aim of this study was to investigate fall-related injuries including healthcare costs among senior citizen pedestrians injured when walking in public outdoor environments and to describe their self-reported causes and suggested preventive strategies. The data were based on a combination of information from injury data and a questionnaire. Three hundred senior citizens attended one emergency department after sustaining injuries from pedestrian falls; 60% suffered nonminor injuries, mostly fractures. One-fifth of the pedestrians were hospitalised for an average of 8 days with an indirect hospital cost of 6.2 million EUR (55 million SEK). Environmental factors such as ice were the most commonly described cause of the injury incident. Forty per cent of the respondents indicated that the municipality was responsible for the cause of the injury incident. Fewer respondents mentioned their own responsibility as a preventive strategy. Thirty per cent described a combination of improvements such as better road maintenance, changes in human behaviour and use of safety products as preventive strategies. It is of great importance to highlight general safety, products and preventive strategies to minimise injury risks, so that pedestrians can safely realise the known health benefits of walking and thereby limit healthcare costs.
Persistent organic pollutants (POPs) are long-range transported to the Arctic via atmospheric and oceanic currents, where they biomagnify to high concentrations in the tissues of apex predators such as polar bears (Ursus maritimus). A major concern of POP exposure is their physiological effects on vital organ-tissues posing a threat to the health and survival of polar bears. Here we examined the relationship between selected POPs and baculum bone mineral density (BMD) in the East Greenland and seven Canadian subpopulations of polar bears. BMD was examined in 471 bacula collected between years 1996-2015 while POP concentrations in adipose tissue were determined in 67-192 of these individuals collected from 1999 to -2015. A geographical comparison showed that baculum BMD was significantly lowest in polar bears from East Greenland (EG) when compared to Gulf of Boothia (GB), Southern Hudson (SH) and Western Hudson (WH) Bay subpopulations (all p?
Many studies have recognized abiotic photochemical degradation as an important sink of methylmercury (CH3Hg) in sunlit surface waters, but the rate-controlling factors remain poorly understood. The overall objective of this study was to improve our understanding of the relative importance of photochemical reactions in the degradation of CH3Hg in surface waters across a variety of marine ecosystems by extending the range of water types studied. Experiments were conducted using surface water collected from coastal sites in Delaware, New Jersey, Connecticut, and Maine, as well as offshore sites on the New England continental shelf break, the equatorial Pacific, and the Arctic Ocean. Filtered water amended with additional CH3Hg at environmentally relevant concentrations was allowed to equilibrate with natural ligands before being exposed to natural sunlight. Water quality parameters - salinity, dissolved organic carbon, and nitrate - were measured, and specific UV absorbance was calculated as a proxy for dissolved aromatic carbon content. Degradation rate constants (0.87-1.67 day-1) varied by a factor of two across all water types tested despite varying characteristics, and did not correlate with initial CH3Hg concentrations or other environmental parameters. The rate constants in terms of cumulative photon flux values were comparable to, but at the high end of, the range of values reported in other studies. Further experiments investigating the controlling parameters of the reaction observed little effect of nitrate and chloride, and potential for bromide involvement. The HydroLight radiative transfer model was used to compute solar irradiance with depth in three representative water bodies - coastal wetland, estuary, and open ocean - allowing for the determination of water column integrated rates. Methylmercury loss per year due to photodegradation was also modeled across a range of latitudes from the Arctic to the Equator in the three model water types, resulting in an estimated global demethylation rate of 25.3 Mmol yr-1. The loss of CH3Hg was greatest in the open ocean due to increased penetration of all wavelengths, especially the UV portion of the spectrum which has a greater ability to degrade CH3Hg. Overall, this study provides additional insights and information to better constrain the importance of photochemical degradation in the cycling of CH3Hg in marine surface waters and its transport from coastal waters to the open ocean.