Uncovering the Ediacaran phosphorus cycle.

Phosphorus is a limiting nutrient that is thought to control oceanic oxygen levels to a large extent1-3. A possible increase in marine phosphorus concentrations during the Ediacaran Period (about 635-539 million years ago) has been proposed as a driver for increasing oxygen levels4-6. However, little is known about the nature and evolution of phosphorus cycling during this time4. Here we use carbonate-associated phosphate (CAP) from six globally distributed sections to reconstruct oceanic phosphorus concentrations during a large negative carbon-isotope excursion-the Shuram excursion (SE)-which co-occurred with global oceanic oxygenation7-9. Our data suggest pulsed increases in oceanic phosphorus concentrations during the falling and rising limbs of the SE. Using a quantitative biogeochemical model, we propose that this observation could be explained by carbon dioxide and phosphorus release from marine organic-matter oxidation primarily by sulfate, with further phosphorus release from carbon-dioxide-driven weathering on land. Collectively, this may have resulted in elevated organic-pyrite burial and ocean oxygenation. Our CAP data also seem to suggest equivalent oceanic phosphorus concentrations under maximum and minimum extents of ocean anoxia across the SE. This observation may reflect decoupled phosphorus and ocean anoxia cycles, as opposed to their coupled nature in the modern ocean. Our findings point to external stimuli such as sulfate weathering rather than internal oceanic phosphorus-oxygen cycling alone as a possible control on oceanic oxygenation in the Ediacaran. In turn, this may help explain the prolonged rise of atmospheric oxygen levels.

Evolution of the global phosphorus cycle.

The macronutrient phosphorus is thought to limit primary productivity in the oceans on geological timescales. Although there has been a sustained effort to reconstruct the dynamics of the phosphorus cycle over the past 3.5 billion years, it remains uncertain whether phosphorus limitation persisted throughout Earth's history and therefore whether the phosphorus cycle has consistently modulated biospheric productivity and ocean-atmosphere oxygen levels over time. Here we present a compilation of phosphorus abundances in marine sedimentary rocks spanning the past 3.5 billion years. We find evidence for relatively low authigenic phosphorus burial in shallow marine environments until about 800 to 700 million years ago. Our interpretation of the database leads us to propose that limited marginal phosphorus burial before that time was linked to phosphorus biolimitation, resulting in elemental stoichiometries in primary producers that diverged strongly from the Redfield ratio (the atomic ratio of carbon, nitrogen and phosphorus found in phytoplankton). We place our phosphorus record in a quantitative biogeochemical model framework and find that a combination of enhanced phosphorus scavenging in anoxic, iron-rich oceans and a nutrient-based bistability in atmospheric oxygen levels could have resulted in a stable low-oxygen world. The combination of these factors may explain the protracted oxygenation of Earth's surface over the last 3.5 billion years of Earth history. However, our analysis also suggests that a fundamental shift in the phosphorus cycle may have occurred during the late Proterozoic eon (between 800 and 635 million years ago), coincident with a previously inferred shift in marine redox states, severe perturbations to Earth's climate system, and the emergence of animals.

[Marie-Victor Ernest Baudrimont, a famous pharmacist from Compiègne, France]. / Marie-Victor Ernest Baudrimont, pharmacien compiégnois.

Ernest Baudrimont is a pharmacist born in Compiègne in 1821. He is the nephew of the pharmacist chemist Alexandre Baudrimont and is from a family of Compiègne pharmacists. First prize and gold medal in 1846 of the School of Pharmacy in Paris, he obtained in 1852 his Ph D in pharmacy for a dissertation on the formation and composition of mineral waters, and in 1864 is Ph D of physical sciences for a dissertation on the chlorides and bromides of phosphorus. Hospitals Chief Pharmacist in 1854, he had his first position at the Sainte Eugénie children's Hospital, today Trousseau hospital in Paris, position he held until 1875 prior to his appointment as Director of the Paris Civilian Hospitals central Pharmacy. Member of the french Botanical Society, the Society of Medical Hydrology, secretary of the Society of Pharmacy, he was also associate professor of Pharmacy at the School of Pharmacy of Paris. His scientific publications focus on the mineral chemistry i.e he described the nature of white phosphorus; mineral waters and some plants chemistry. One of the major contributions of Ernest Baudrimont was his involvment to the successive editions of the dictionary of the alterations and falsifications of foodstuffs of A. Chevallier. Member of the french Academy of Medicine in 1881, he died in Paris in September 1885.

Phosphorus: the philosopher's stone discovered in 1669.

Recently the importance in nephrology of phosphorus as phosphate has been highlighted by chronic renal failure patients, in whom the toxic effect of phosphate is widely acknowledged, given the association of phosphate serum level with cardiovascular risk. This association is not limited to chronic renal failure and hemodialysis patients as high serum phosphate. Recently high serum phosphate levels were associated with increased risk for cardiovascular disease in subjects free from chronic kidney disease, and cardiovascular disease as well, and with progression of atherosclerosis. It is useful to know the history of phosphorus from its discovery in 1669, because that history gives us more evidence to better understand the negative and/or toxic effects of high phosphate serum levels and to identify phosphorus as a physiologically crucial anion.

Hot dog? Toxicological concerns and The Hound of the Baskervilles.

The terrifying dog in the Hound of the Baskervilles is described as having 'blazing eyes' and a 'luminous muzzle', appearances attributed by Watson and Holmes to the application of phosphorus. Review of the toxicity and flammability of white phosphorus make this improbable. It is suggested that Conan Doyle's description was probably influenced by knowledge of the recent and much publicized discovery of luminescence due to the radioactivity of uranium salts.

Declining ambient water phosphorus concentrations in Massachusetts' rivers from 1999 to 2013: Environmental protection works.

Over the last century, nutrient concentrations in streams, rivers, lakes and ponds have increased substantially in the United States. Elevated phosphorus levels are a concern due to their ability to cause changes in freshwater ecosystems that are detrimental to humans and wildlife. In the present study, long-term trends in total phosphorus (TP) concentrations from 20 rivers in central Massachusetts from 1999 to 2013 were investigated. Kendall's correlation coefficients were used to demonstrate that 18 of the 20 rivers had significant reductions in TP concentrations (P < 0.05). A similar trend was found when flow-adjusted TP concentrations were analyzed. At the beginning of monitoring activities, the average TP concentration in 9 of the 20 rivers was greater than 0.05 mg/L and 6 of these 9 rivers contained TP concentrations greater than 0.1 mg/L; about fifteen years later, only 3 rivers contained TP greater than 0.05 mg/L and none had concentrations> 0.1 mg/L. TP decreases were greater in rivers with more anthropogenic inputs. Principal component analysis (PCA) revealed that the decline of TP in these Massachusetts streams is likely the result of advancements in wastewater treatment and implementation of effective non-point source management practices.

Historical eutrophication in a river-estuary complex in mid-coast Maine.

European settlement of New England brought about a novel disturbance regime that impacted rivers and estuaries through overfishing, deforestation, dams, and water pollution. The negative consequences of these activities intensified with industrialization in the 19th and 20th centuries, often resulting in ecosystem degradation. Since environmental legislation was implemented in the 1970s, improvement in water quality has been tangible and widespread; however, ecological recovery can require substantial amounts of time and may never be complete. To document the natural baseline conditions and investigate the recovery of a severely degraded river-estuary complex in mid-coast Maine, we examined diatoms, pollen, total organic carbon, total nitrogen, stable isotopes, total phosphorus, biogenic silica, and trace metals in intertidal sediments and established a chronology with 14C, 210Pb, and indicator pollen horizons. Both climate variability and human effects were evident in the sedimentary record of Merrymeeting Bay, the freshwater tidal portion of the Kennebec estuary. Natural climate variability was apparent in an episode of high sedimentation and altered diatom abundance during the 12th and 13th centuries and in changing pollen abundances between the 16th and 19th centuries, indicative of regional cooling. During the 18th century, colonial land clearance began an era of high sedimentation and eutrophication that strongly intensified with industrialization during the late 19th and 20th centuries. Improvements in water quality over the past 30 years in response to environmental regulation had little effect on ecosystem recovery as represented by the sedimentary record. Diatom composition and productivity and high fluxes of organic C, total P, and biogenic Si in recent sediments indicate that rates of nutrient loading remain high. These environmental proxies imply that aquatic productivity in Merrymeeting Bay was originally nutrient limited and water clarity high, relative to today. Further recovery may require more stringent regulation of nutrient inputs from industrial and municipal point sources. This historical study can contribute to public debate about the environmental management of this unusual river-estuary complex by describing its long-term natural baseline, thereby illustrating the upper limit of its potential for recovery.

Spatial and historical variation in sediment phosphorus fractions and mobility in a shallow lake.

Temporal and spatial variation in sediment P composition and mobility were investigated in Loch Leven. Little change was observed in total sediment P (surface sediment at 4m depth), in comparison to a previous study (1990), despite significant reduction of external point sources of P. Labile P and residual P have both increased (0.007-0.039 mg PO(4)-P and 0.121-0.420 mg PO(4)-P per gram dry weight of sediment, respectively) since 1990. An analysis of P fractions, along a depth transect, indicated elevated labile P concentrations in shallow water sediment (<12 m overlying water depth). Regression analysis showed that spatial variability in reductant-adsorbed P was significantly related to sediment chlorophyll a concentration (R(2)=0.733, p<0.05). This may be linked to the production of oxygen, by benthic algae, resulting in the maintenance of an oxygenated layer at the sediment surface. Variation in labile P was best explained by overlying water temperature and equilibrium phosphate concentration (EPC0).

Between the utility and hazards of phosphorus through the centuries.

Phosphorus has been shown to be a predictor of cardiovascular mortality in kidney disease subjects. Phosphorus was discovered in 1669 and was considered a philosophers stone, it was used as medicament but there were reported deaths after its use. High serum levels of phosphorus are associated with increased risk for cardiovascular disease in the general population in subjects free from chronic kidney disease. Phosphorus can be defined as a useful and hazardous element for public health.

Decadal change in vegetation and soil phosphorus pattern across the Everglades landscape.

Wetlands respond to nutrient enrichment with characteristic increases in soil nutrients and shifts in plant community composition. These responses to eutrophication tend to be more rapid and longer lasting in oligotrophic systems. In this study, we documented changes associated with water quality from 1989 to 1999 in oligotrophic Everglades wetlands. We accomplished this by resampling soils and macrophytes along four transects in 1999 that were originally sampled in 1989. In addition to documenting soil phosphorus (P) levels and decadal changes in plant species composition at the same sites, we report macrophyte tissue nutrient and biomass data from 1999 for future temporal comparisons. Water quality improved throughout much of the Everglades in the 1990s. In spite of this improvement, though, we found that water quality impacts worsened during this time in areas of the northern Everglades (western Loxahatchee National Wildlife Refuge [NWR] and Water Conservation Area [WCA] 2A). Zones of high soil P (exceeding 700 mg P kg(-1) dry wt. soil) increased to more than 1 km from the western margin canal into the Loxahatchee NWR and more than 4 km from northern boundary canal into WCA-2A. This doubling of the high soil P zones since 1989 was paralleled with an expansion of cattail (Typha spp.)-dominated marsh in both regions. Macrophyte species richness declined in both areas from 1989 to 1999 (27% in the Loxahatchee NWR and 33% in WCA-2A). In contrast, areas well south of the Everglades Agricultural Area, induding WCA-3A and Everglades National Park (ENP), did not decline during this time. We found no significant decadal change in plant community patterns from 1989 and 1999 along transects in southern WCA-3A or Shark River Slough (ENP). Our 1999 sampling also included a new transect in Taylor Slough (ENP), which will allow change analysis here in the future. Regular sampling of these transects, to verify decadal-scale environmental impacts or improvements, will continue to be an important tool for long-term management and restoration of the Everglades.

The history of cyanobacterial blooms in the Baltic Sea.

Long-term information on possible changes in cyanobacterial blooms in the Baltic Sea, formed mainly by Nodularia spumigena and Aphanizomenon sp., was sought in published records in historical (years 1887-1938) and modern (years 1974-1998) phytoplankton data sets. Old and new sampling methods and fixatives were tested to improve the comparison of data that had been collected and analyzed in different ways. A hundred years ago, plankton was mainly of interest as a source of fish food; eutrophication problems were only locally reported from the coast, mainly in southern haffs and the receiving waters of larger cities. There were few recordings of open-sea blooms before World War II. Abundances of Nodularia spumigena and Aphanizomenon sp. were low in the old material, and 137 summer samples from 1887-1938 showed no peak abundance. High abundances are common in the new material, and the range of the numbers of both taxa has increased markedly relative to the old material. Since the 1960s, cyanobacterial blooms have been common in the open sea in both the Baltic proper and the Gulf of Finland, indicating high availability of nutrients.

The pollution and protection of the inner Oslofjord: redefining the goals of wastewater treatment policy in the 20th century.

The main source of pollution in the inner Oslofjord in the 20th century has been municipal sewage discharges from the city of Oslo. At the beginning of the 20th century, pollution was limited to the coastal waters and the harbor area of Oslo, in the vicinity of sewer outlets. High bacteria content caused a health hazard that city authorities attempted to reduce by constructing a sewerage system, including intercepting sewers and wastewater-treatment plants. Due to population growth, the impact area of increasing wastewater loading expanded. The entire inner Oslofjord was found to be affected in the 1930s. Scientific studies linked municipal sewage discharges to an increase in the algal production. In the 1940s, the bottom layers were found to be anoxic. The Oslo sewerage authorities were aware of the fjord's pollution, but regarded organic matter as the major problem and the activated sludge method as the best solution. The role of nutrients was not commonly acknowledged until in the late 1960s. Phosphorus removal was taken into use in the 1970s, and nitrogen removal was introduced in the late 1990s. Removal of nutrients has resulted in the slow recovery of the fjord.

Understanding human impact on the Baltic ecosystem: changing views in recent decades.

Grave environmental problems, including contamination of biota by organochlorines and heavy metals, and increasing deep-water oxygen deficiency, were discovered in the Baltic Sea in the late 1960s. Toxic pollutants, including the newly discovered PCB, were initially seen as the main threat to the Baltic ecosystem, and the impaired reproduction found in Baltic seals and white-tailed eagles implied a threat also to human fish eaters. Countermeasures gradually gave results, and today the struggle to limit toxic pollution of the Baltic is an international environmental success story. Calculations showed that Baltic deep-water oxygen consumption must have increased, and that the Baltic nutrient load had grown about fourfold for nitrogen and 8 times for phosphorus. Evidence of increased organic production at all trophic levels in the ecosystem gradually accumulated. Phosphorus was first thought to limit Baltic primary production, but measurements soon showed that nitrogen is generally limiting in the open Baltic proper, except for nitrogen-fixing cyanobacteria. Today, the debate is concerned with whether phosphorus, by limiting nitrogen-fixers, can control open-sea ecosystem production, even where phytoplankton is clearly nitrogen limited. The Baltic lesson teaches us that our views of newly discovered environmental problems undergo repeated changes, and that it may take decades for scientists to agree on their causes. Once society decides on countermeasures, it may take decades for them to become effective, and for nature to recover. Thus, environmental management decisions can hardly wait for scientific certainty. We should therefore view environmental management decisions as experiments, to be monitored, learned from, and then modified as needed.

Effect of water quality management efforts on wastewater loadings during the past century.

The history of wastewater discharges to the Hudson River watershed from Troy, New York, to the New York City Harbor was traced from 1900 to 2000. The parameters studied include population, flow, type of treatment, biochemical oxygen demand, suspended solids, total nitrogen, and total phosphorus. This paper details a methodology for estimating historic loadings where data are lacking. The data show dramatic changes in wastewater loadings. There has been a continued increase in wastewater flow and population over the past century but a decrease in contaminant loading during the last 25 years. The reduction in effluent loads is directly related to state and federal water quality management programs and the substantial public and private investment made in upgrading point source water pollution control infrastructure. A comparison of point with nonpoint source loads shows that although nonpoint sources are now a significant contributor of contaminants to the river, point sources remain as major sources of total nitrogen and total phosphorus.

Light and enlightenment: Cabanis, ideology, and the role of phosphorus in the brain.

When Georges Cabanis presented his views to the National Institute of France in 1797 on the physiological basis of human psychology, he introduced the concept that phosphorus was of special importance in the workings of the brain. The presence of phosphorus in that organ had only recently been described by A F Fourcroy, a finding that impressed Cabanis because of the association of light (phosphorescence) and heat (evolved during oxidation) with the element. Furthermore, he hypothesised that the electrical activity of the brain represented a parallel and interacting system with that of phosphorus. Cabanis was one of the leading exponents of "ideology", the principal school of philosophy at the time of the French Revolution. Ideology promoted the systematisation of knowledge in every sphere--social, scientific and medical, for example-- and Cabanis's views about cerebral phosphorus evolved from those teachings.

An element of thought: phosphorus and mental philosophy in the nineteenth century.

Georges Cabanis (1757-1808), through his writings on the relation of the physical and moral, or psychological, aspects of man, left a legacy that made the study of mental activity a part of physiology. His views on the importance of phosphorus to the function of the brain thrust that element into a prominent stream of research that involved many investigators in several countries. Although that particular stream eventually dried up, its influence remained: by the beginning of the twentieth century basic medical science had become well set on studies of the mind-body relationship.

[Ca and P supply of ruminants in the 19th and beginning of 20th century in Middle Europe]. / Zur Ca- und P-Versorgung der Wiederkäuer im 19. und beginnenden 20. Jahrhundert in Mitteleuropa.

The present review evaluates veterinary publications about some bone diseases in ruminants till 1925. According to more than 100 publications in some regions of Germany as well as in Scandinavian and Westeuropean countries during the 19th century several cases of bone fractures in ruminants were reported, mainly in pregnant and lactating cattle and goats. From a recent point of view and after feed analyses this disease obviously was caused by a P-deficiency. Bone fractures sometimes were accompanied by licking behaviour, but in other regions pica (without severe skeletal deformations) was probably related to a Cu- or Co-deficiency. Swelling of the jaws (probably by Ca-deficiency) was exclusively described in goats. By preventive measures (feeding bone meal, P-fertilisation) bone fractures diminished in the beginning of the 20th century. After the experience in the past in ruminants bone diseases may come back, if effective preventive measures will be ignored due to the recent trends towards 'natural farming'.

[Doctor of medicine Awit Reniger (1853-1907) and his doctorate dissertation]. / Awit Reniger (1853-1907) i jego rozprawa na stopien doktora medycyny.

The author announced main details of Awit Reniger's life, main thesis and conclusions of his doctorate dissertation. Doctor's Thesis concerning: Pathological changes in the anatomy of marrow in cases of the phosphorus intoxication. This dissertation is not reported in S. Konopka's: Polish medical bibliography of the nineteenth century (1801-1900).

[The French matches or the singular history of poisonings by the white phosphorus]. / Les allumettes françaises ou la singulière histoire des empoisonnements par le phosphore blanc.

The history of phosphorus poisonings is dominated by the existence of two allotropic forms, the red phosphorus, without toxicity and the white phosphorus, causing very severe necrosis. Although phosphorus has been isolated in 1669, it is mainly during the first part of the Nineteen century that numerous accidental or criminal poisonings by this metalloid were observed, linked to the extensive use of the whie phosphorus in French matches. Some interesting stories of phosphorus poisoning have been described by A. Tardieu and F. Z. Roussin in Etude médico-légale et clinique de l'empoisonnement, published in 1867. During this period, several pharmacists were strongly implicated in the analytical toxicology of phosphorus.