Five well-known imputation packages accessible in R were applied. The first R package used here was VIM (), which is associated with kNN imputation methods and robust model-based imputation for numerical, semi-continuous, categorical, or ordered variables []. The second R package was MICE () which stands for Multivariate Imputation via Chained Equations []. MICE is specialized to deal with missing values of MAR or MNAR types []. MICE can deal with different types of variables using different imputation methods, such as predictive mean matching for numeric variables, logistic regression for binary variables, Bayesian polytomous regression for factor variables, and a proportional odds model for ordered variables [,]. The third package was missForest (). MissForest deals with non-parametric imputation []. MissForest enables the imputation of the predictors by using regression trees of resampling under the prediction classification of missing values []. MissForest has good computational efficiency and can work well with high-dimensional data []. The fourth package was Amelia (), which enables imputation by maximizing the level of expectation with a bootstrapping algorithm. The Amelia package has also been recommended under a larger number of variables with high-dimensional data. The package also provides improved imputation models by adding Bayesian priors on individual cell values []. The final package used was missCompare (). The missCompare package provides several diagnostic measurements to compare between all imputation methods, using RMSE, MAE, and other imputation performance criteria.3. Statistical Results, Logarithm transformation was carried out for all pollutant data, in order to normalize their distributions and to minimize skewness. We found high levels of missing values for N O 2 (18.4%), C O (18.5%), P M 10 (57.4%), S O 2 (19.0%), and O 3 (18.2%) data., Overall the amount of missing data in 2010 is roughly 32.1%. Not only do we compare the predictive performances following the application of different PCA methods, but we also examine how different the chemical profiles are when considering only complete sites versus all available data..