{"schemaVersion":"realm.silica.v1","mineId":"1502225","mineName":"No C-66 Mine","filters":{"year":"2026","dataset":"all","status":"all"},"options":{"years":["2026"],"datasets":{"coal":{"id":"msha-quartz-samples","label":"Coal quartz","definitionUrl":"https://arlweb.msha.gov/OpenGovernmentData/DataSets/Quartz_Samples_Definition_File.txt"},"personal":{"id":"msha-personal-health-samples","label":"Metal/nonmetal personal","definitionUrl":"https://arlweb.msha.gov/OpenGovernmentData/DataSets/Personal_Health_Samples_Definition_File.txt"},"area":{"id":"msha-area-samples","label":"Metal/nonmetal area","definitionUrl":"https://arlweb.msha.gov/OpenGovernmentData/DataSets/Area_Samples_Definition_File.txt"}},"statuses":{"not_voided":"Not voided","voided":"Voided","not_reported":"Not reported"}},"coverage":{"scope":"full_mine_history","totalSilicaRows":0,"sourceCoverage":[{"dataset":"coal","sourceRows":0,"retainedRows":0},{"dataset":"personal","sourceRows":0,"retainedRows":0},{"dataset":"area","sourceRows":0,"retainedRows":0}],"invalidOrFutureDateRows":0,"firstDate":null,"lastDate":null},"summary":{"total":0,"coal":0,"personal":0,"area":0,"notVoided":0,"voided":0,"statusNotReported":0,"coalMeasured":0,"coalMissingConcentration":0,"coalMeanUgM3":null,"coalMaxUgM3":null,"personalMeasured":0,"personalAbovePublishedLimit":0},"quarters":[{"quarter":"2026-Q1","coalMeanUgM3":null,"coalMeasurementCount":0,"personalMeanExposureRatio":null,"personalMeasurementCount":0,"partialQuarter":false},{"quarter":"2026-Q2","coalMeanUgM3":null,"coalMeasurementCount":0,"personalMeanExposureRatio":null,"personalMeasurementCount":0,"partialQuarter":false},{"quarter":"2026-Q3","coalMeanUgM3":null,"coalMeasurementCount":0,"personalMeanExposureRatio":null,"personalMeasurementCount":0,"partialQuarter":false},{"quarter":"2026-Q4","coalMeanUgM3":null,"coalMeasurementCount":0,"personalMeanExposureRatio":null,"personalMeasurementCount":0,"partialQuarter":true}],"data":[],"pagination":{"page":1,"pageSize":20,"totalRows":0,"totalPages":1},"units":{"quartzPercent":"%","quartzConcentrationUgM3":"µg/m³","exposureRatio":"concentration / published exposure limit","sourceConcentration":"Unit not specified in MSHA personal/area data dictionary; retained as reported"},"notes":["Coal means use numeric concentrations from samples marked not voided, excluding control/invalid sample types and dates after the snapshot. Missing values remain null; reported zeroes remain zero.","Quarterly means describe available samples, not mine-wide or worker-average exposure. Quarters with no eligible measurements remain empty; the current quarter is partial.","Personal C/E is MSHA's published concentration-to-limit ratio. A value above 1 is not by itself a citation or a determination under the 2024 silica rule. Personal and area files do not publish a void-status field.","Area records include bulk-dust analyses and are kept separate from personal exposure results. Their concentration units are not specified in the source dictionary.","Missing samples do not establish safe conditions. Coal quartz percentage and concentration are separate measures. No compliance threshold is inferred for coal samples."],"meta":{"dataSource":"postgres","snapshotId":"2026-10-13T11:19:05.459773+00:00","completedAt":"2026-10-13T11:26:59.000Z","sourceCount":20,"totalRows":17906804,"snapshotAt":"2026-10-13T11:19:05.459773+00:00"}}