Study of PM10 and PM2.5 levels in three European cities: Analysis of intra and inter urban variations

In the present paper, 1-year PM10 and PM 2.5 data from roadside and urban background monitoring stations in Athens (Greece), Madrid (Spain) and London (UK) are analysed in relation to other air pollutants (NO,NO2,NOx,CO,O3 and SO2)and several meteorological parameters (wind velocity, temperature, relative humidity, precipitation, solar radiation and atmospheric pressure), in order to investigate the sources and factors affecting particulate pollution in large European cities. Principal component and regression analyses are therefore used to quantify the contribution of both combustion and non-combustion sources to the PM10 and PM 2.5 levels observed. The analysis reveals that the EU legislated PM 10 and PM2.5 limit values are frequently breached, forming a potential public health hazard in the areas studied. The seasonal variability patterns of particulates varies among cities and sites, with Athens and Madrid presenting higher PM10 concentrations during the warm period and suggesting the larger relative contribution of secondary and natural particles during hot and dry days. It is estimated that the contribution of non-combustion sources varies substantially among cities, sites and seasons and ranges between 38-67% and 40-62% in London, 26-50% and 20-62% in Athens, and 31-58% and 33-68% in Madrid, for both PM10 and PM 2.5. Higher contributions from non-combustion sources are found at urban background sites in all three cities, whereas in the traffic sites the seasonal differences are smaller. In addition, the non-combustion fraction of both particle metrics is higher during the warm season at all sites. On the whole, the analysis provides evidence of the substantial impact of non-combustion sources on local air quality in all three cities. While vehicular exhaust emissions carry a large part of the risk posed on human health by particle exposure, it is most likely that mitigation measures designed for their reduction will have a major effect only at traffic sites and additional measures will be necessary for the control of background levels. However, efforts in mitigation strategies should always focus on optimal health effects.

Observations of Sun Spots, 1739-1743

Eleven-page notebook containing John Winthrop's handwritten observations and calculations. Titled by Winthrop "Observations of 'Spots' on ye Sun with ye Naked Eye," this is the first known record of his scientific observations and records what he saw while examining the sun "with an 8 foot telescope from 6 a.m. til sun set" on the Boston Commons and concluding with "a considerable aurora borealis" that night (April 20, 1739). It has been speculated that his reference to the aurora borealis in these observations may indicate that he recognized the interrelation of the aurora borealis and sun spots, a concept which was not definitively established until the mid-nineteenth century.

Clipping from The Harvard Bulletin, on discovery of southeast corner of original Harvard College building during subway excavations, 1910.

Contains prints of floor plans of Harvard College used for publication by Samuel E. Morison.

Bill of mortality for ten years at Cambridge (manuscript chart), [1768]

One folded leaf containing a chart in John Winthrop's hand listing the number of deaths by month for 1759-1768 and listing the chief causes of mortality. The verso contains a list of the number of deaths by year according to age groups.

The Summary of a Course of Experimental Philosophical Lectures, 1746-1747

Leather hardcover notebook containing a handwritten copy of John Winthrop's course of experimental and philosophical lectures presented between March 10, 1746 and June 16, 1746. The first one-hundred pages of the volume are divided into twenty chapters which were presented in thirty-three lectures. The chapters contain text and diagrams on mechanical powers, the lever, the pulley, the axis in peritrochio, the inclined plane, the wedge, the screw, compound engines, the laws of motion, gravity, attraction of cohesion, the power of repulsion, magnetism, fluids, electricity, opticks, and astronomy. There is a five-page addenda to the course summary added in 1747, and a sixty-page text titled "The Method of Astronomical calculations" containing thirteen problems related to calculating distances with a list of astronomical characters, and followed with charts related to the eclipse of Jupiter's satellites.

[Ethics and Moral Philosophy book list, 1790]

One leaf containing a handwritten list of books with one column marked "Ethics" and the other column marked "Moral Philosophy." Entries contain the author's last name and abbreviated title. The page is inscribed "Vose," likely referring to Roger Vose (Harvard AB 1790), and the verso has a fragment of a poem.

[Ethics and moral philosophy book list, 1790]

One leaf containing a handwritten list of books generally on ethics and moral philosophy, though no subject is identified. Entries contain the author's last name and abbreviated title. The page is inscribed "Paine," likely referring to Robert Treat Paine (Harvard AB 1792), and the verso has a fragment of a student essay on the theme "An undevout astronomer is mad," signed "Paine."

Resolution of the committee concerning the way through Rogers's farm, 1762 February 27

One octavo-sized leaf containing a one-page handwritten draft of a resolution by a Harvard Corporation Committee appointed to "lay out an High Way thro' Rogers's Farm & determine about the Cost of the Sd way & the making the fences to enclose it." The resolution permits the town of Waltham to lay a highway on the farm's property as long as it is enclosed by a stone wall.

Report of the Secretary of Agriculture and Commerce.

Some reports issued as part of the Philippine agricultural review.

Bulletin of bibliography and dramatic index.

Title varies slightly.

Annual report of the Bureau of Mines and Mining of the State of Indiana.

Mode of access: Internet.

Studies in the anthropology of Bougainville, Solomon Islands /

Mode of access: Internet.

A history of the mathematical theories of attraction and the figure of the earth from the time of Newton to that of Laplace.

Available on demand as hard copy or computer file from Cornell University Library.