31 research outputs found
A compilation of global bio-optical in situ data for ocean colour satellite applications – version three
A global in situ data set for validation of ocean colour products from the ESA Ocean Colour Climate
Change Initiative (OC-CCI) is presented. This version of the compilation, starting in 1997, now extends to
2021, which is important for the validation of the most recent satellite optical sensors such as Sentinel 3B
OLCI and NOAA-20 VIIRS. The data set comprises in situ observations of the following variables: spectral remote-sensing reflectance, concentration of chlorophyll-a, spectral inherent optical properties, spectral diffuse
attenuation coefficient, and total suspended matter. Data were obtained from multi-project archives acquired via
open internet services or from individual projects acquired directly from data providers. Methodologies were
implemented for homogenization, quality control, and merging of all data. Minimal changes were made on the
original data, other than conversion to a standard format, elimination of some points, after quality control and
averaging of observations that were close in time and space. The result is a merged table available in text format.
Overall, the size of the data set grew with 148 432 rows, with each row representing a unique station in space
and time (cf. 136 250 rows in previous version; Valente et al., 2019). Observations of remote-sensing reflectance
increased to 68 641 (cf. 59 781 in previous version; Valente et al., 2019). There was also a near tenfold increase
in chlorophyll data since 2016. Metadata of each in situ measurement (original source, cruise or experiment,
principal investigator) are included in the final table. By making the metadata available, provenance is better
documented and it is also possible to analyse each set of data separately. The compiled data are available at
https://doi.org/10.1594/PANGAEA.941318 (Valente et al., 2022)
Methyl methacrylate and respiratory sensitization: A Critical review
Methyl methacrylate (MMA) is a respiratory irritant and dermal sensitizer that has been associated with occupational asthma in a small number of case reports. Those reports have raised concern that it might be a respiratory sensitizer. To better understand that possibility, we reviewed the in silico, in chemico, in vitro, and in vivo toxicology literature, and also epidemiologic and occupational medicine reports related to the respiratory effects of MMA. Numerous in silico and in chemico studies indicate that MMA is unlikely to be a respiratory sensitizer. The few in vitro studies suggest that MMA has generally weak effects. In vivo studies have documented contact skin sensitization, nonspecific cytotoxicity, and weakly positive responses on local lymph node assay; guinea pig and mouse inhalation sensitization tests have not been performed. Cohort and cross-sectional worker studies reported irritation of eyes, nose, and upper respiratory tract associated with short-term peaks exposures, but little evidence for respiratory sensitization or asthma. Nineteen case reports described asthma, laryngitis, or hypersensitivity pneumonitis in MMA-exposed workers; however, exposures were either not well described or involved mixtures containing more reactive respiratory sensitizers and irritants.The weight of evidence, both experimental and observational, argues that MMA is not a respiratory sensitizer