A Study on Causal Relationships Between Working Conditions and Occupational Diseases: A Case Study of a Phosphorus Plant in Kazakhstan

This article examines the relationship between working conditions and the development of work-related diseases at a phosphorus plant.An analysis of occupational risks was conducted based on indicators of relative risk (RR) and etiologic fraction (EF), using data from medical examinations, temporary disability morbidity, and working conditions assessments.The study involved 1,162 workers, of whom 1,021 comprised the experimental group (employees from five workshops of the phosphorus plant exposed to harmful factors), and 141 formed the control group, with no exposure to hazardous occupational factors.By comparing the levels of morbidity, injury, and occupational pathology between these groups, significant differences were found in the levels of risk and the degree of professional conditioning of diseases.The analysis revealed that the highest levels of occupational risk were identified in Workshop No. 12 (RR=4.3;EF=76.7%) and Workshop No. 5 (RR=2.5;EF=60.64%),indicating a strong occupational attribution of the detected pathologies, primarily affecting the sensory and respiratory systems.A moderate level of risk was established in Workshop No. 7 (RR=1.6;EF=37.5%) and was predominantly associated with musculoskeletal disorders.In contrast, Workshops No. 2 (RR=1.1;EF=9.1%) and No. 1 (RR=0.7;EF=-42.9%)demonstrated low risk levels, suggesting a weak or negligible association between working conditions and workers' health outcomes.Models were constructed to show the relationship between RR, the number of cases, and the etiological fraction, reflecting the contribution of production factors to the development of occupational pathology.Strongly significant correlations were found between the impact factors (noise, dust, chemicals) and the morbidity rates of workers.A strong positive correlation was established between the level of inorganic dust (quartzite) and the frequency of upper respiratory diseases (r= 0.97, p<0.01), as well as between dust from inorganic materials (coke, phosphate, gypsum) and the frequency of upper respiratory diseases (r=0.84,p<0.01).The correlation between noise levels and sensory diseases (r=0.40,p<0.05) confirmed the impact of physical factors on workers health.Based on the obtained results, a matrix for assessing working conditions was developed, taking into account the new classification of harmful factors proposed in Kazakhstan.The results presented can be used for the prevention of occupational diseases and the optimization of working conditions at industrial enterprises.